The high seeds just keep tumbling out of the women’s field at the Sony Ericsson Open.

Jelena Jankovic and Dinara Safina injected shock value into the weekend with early-round stumbles at the Crandon Park Tennis Center, but by the time darkness fell on a crazy Sunday, two more bombshells did further damage to a bracket that has lost all sense of order.

Just when South Florida tennis fans were recovering from Jankovic’s Saturday night surprise, Sunday bagged three of the top seven seeds at this 96-player event. Safina, the No. 2 seed, joined Jankovic on the sidelines with a late-morning loss to Samantha Stosur. After that eye-popping result, the chaos kept on coming as a significant Sunday unfolded.

No. 7 Ana Ivanovic and sixth-seeded Vera Zvonareva became the latest casualties of an already-wacky tournament, bowing out of Miami before the round of 16. Ivanovic lost to Agnes Szavay, 6-4, 4-6, 6-1, while Zvonareva fell to Na Li, 6-4, 3-6, 6-2. The pair of third-round results conveyed a telling and timely message to tennis aficionados, reminding the followers of this sport why elite-level excellence is so difficult to sustain.

As mentioned earlier today in another post, the losses suffered by Jankovic and Safina were simply inexcusable, because the third-seeded Serb and the second-seeded Russian both enjoyed extra degrees of rest after the BNP Paribas Open at Indian Wells. If the California part of this United States tennis journey doesn’t work out, an elite player should bounce back with a solid swing through Florida on the back end. Jankovic and Safina couldn’t do the deed.

For Ivanovic and Zvonareva, the outlook is decidedly different.

Precisely one week ago–on Sunday, March 22–Ivanovic and Zvonareva did battle in the Indian Wells final. Having endured more than a week of top-flight tennis in the California desert, Ivanovic and Zvonareva then had to fight their way through a wind-blown championship match (won by Zvonareva) that strained their nerves and tested their focus. The two female tennis players who traveled to Miami with the least amount of fuel in the competitive tank were the 21-year-old Serb and the 24-year-old Russian.

It’s been said before, but it bears repeating: The Indian Wells-Miami double is the toughest two-tournament turnaround in professional tennis. Rare is the soul, male or female, who can excel at both events and play nearly three weeks’ worth of matches in a four-week time frame. This simple but important part of life on the professional tennis tour should give comfort to the members of the Ivanovic and Zvonareva fan clubs.

Ana’s admirers shouldn’t be discouraged by an inconsistent showing against Szavay, a Hungarian with ample talent and a No. 25 world ranking. Ivanovic said after the loss that she was a little bit off throughout the match; that’s what the rigors of the Indian Wells-Miami double will do to the players who extend themselves in at least one of the two events.

Those who throw their support behind Zvonareva should be similarly serene about their heroine’s fate. There’s no shame in losing to Li, a 40th-ranked foe who reached the fourth round at last September’s U.S. Open and is still a competitive force on the WTA Tour at 27, a tennis equivalent of middle age. There are occasions when a loss signifies an alarming lack of confidence or glaring deficiencies in a player’s competitive makeup; this defeat to a worthy Chinese challenger is not one of them. With time for rest and renewal, Zvonareva should find herself very much in the mix when the second half of April ushers in the clay season.

Ana Ivanovic and Vera Zvonareva should feel good about the month of March. Whereas some of their competitors truly faltered in Miami, these two young women should not be discouraged by their own early-round losses.

The WTA Tour portion of the Sony Ericsson Open represents a bomb shelter after a wild weekend in South Florida.

Before the round of 16 begins, the women’s bracket has already been blown wide open. Third-seeded Jelena Jankovic lost to Gisela Dulko in the second round on Saturday night, 6-4, 7-6 (5), while second-seeded Dinara Safina crashed out of Miami in third round action on Sunday, bowing to Samantha Stosur in straight sets, 6-4, 6-1.

There were other upsets to be found at the Crandon Park Tennis Center, but for now, let’s take a look at the two huge disappointments to emerge from the women’s draw.

Jankovic and Safina have very little excuse for not making a reasonably deep run (the quarterfinals at minimum) in the last hardcourt event before the spring clay season. Jankovic lost her first match at Indian Wells two weeks ago, which meant that the 2008 U.S. Open runner-up enjoyed more rest coming into this event than most of her peers on tour. The failure to win a single match in the two most important non-Grand Slam events of the year represents a huge blot on the resume of a woman who still enjoys a top-five world ranking. Jankovic, who lost in the fourth round at this year’s Australian Open, has seen her fortunes plummet after a strong conclusion to her 2008 season. Consistency defines elite tennis players, and for Jankovic, the milestone of her first Slam final (last September in New York) has been followed by ambush losses more than by reputation-enhancing victories. If anyone in the WTA needs a bounce-back clay season, it’s Jankovic.

For Safina, the story of this Miami meltdown also offers cause for concern, only on a smaller scale than Jankovic. Safina–the 2009 Australian Open runner-up–pieced together a decent Indian Wells event by reaching the quarterfinals, but such a showing still enabled the Russian to get out of California well before the final weekend of that particular competition. Turnaround time in Miami was substantial for the younger sister of Marat Safin; another quarterfinal result was certainly expected on America’s other coastline.

The hard reality for Safina to digest isn’t necessarily her early-round defeat, but the way in which it happened. Stosur, an Australian ranked 42nd in the world, has very few major achievements to her credit as a singles player. Stosur owns 22 career doubles titles, but has never made the quarterfinals of a single slam tournament. For a player of Safina’s caliber to win only five games against Stosur is nothing less than a complete train wreck. That’s not what a No. 2 seed should do in an event of appreciable stature.

The women’s tennis world is left with a weird yet undeniable storyline: The losers of the last two Grand Slam singles finals have both spiraled downward in the months following their moments in the spotlight. The greatest winners handle the heat, no matter the time or season. Jelena Jankovic and Dinara Safina have found themselves in the thick of championship matches at major events, but if they don’t learn how to develop more consistency on tour, their careers will fall short of their considerable potential.

Andy Murray didn’t bench press 600 pounds or stop a criminal in a back alley on a humid Saturday afternoon in Miami. He did, however, prove his toughness to his peers.

Murray withstood the hard hitting of Argentina’s Juan Monaco to pull out a 4-6, 6-3, 6-2 victory in just over two hours. The second-round win not only kept the world’s No. 4 player alive at the Sony Ericsson Open; the three-set triumph revealed why the Scot has become an elite tennis player who seems destined for glory in the very near future.

The two toughest weeks on the ATP Tour might be found at the French Open, because of the grueling nature of clay court tennis. Others would contend that the U.S. Open offers the most draining weeks on the tennis calendar, given the fact that the year’s last Grand Slam comes at the end of a punishing summer hardcourt season. One could have a vigorous and spirited debate about the two toughest weeks in men’s tennis.

With that having been said, there’s very little question that the toughest two-tournament sequence for any professional tennis player involves the two “mini-majors,” otherwise known as the early Spring swing between the Indian Wells and Miami events. The transition between the BNP Paribas Open and the Sony Ericsson Open is a brutal one for every participant, mentally and physically. Players who fail at Indian Wells receive off time before Miami, but those who make a deep run on America’s West Coast find themselves deprived of an ability to recuperate for the East Coast event that arrives in a very short period of time.

To take just one example, Ivan Ljubicic– a quarterfinalist in Indian Wells this year–tumbled out of Key Biscayne with a first-round loss. Very rare is the player who can make deep runs in both California and Florida in the second half of March; those who pull off the feat represent the elite performers in the men’s game.

On Saturday at the Crandon Park Tennis Center, Murray stamped himself as just such a specimen.

Monaco established considerable shot penetration from both wings, catching Murray and the stadium court crowd by surprise. The Argentine led throughout a first set that he polished off when three Murray forehands went astray. Down by a set, the Scot–who played last Sunday in the Indian Wells final–had a chance to mentally check out of the event and be satisfied with his strong showing in California.

Instead, Murray wanted to play on in South Florida, proving that his competitive juices flow more fully than most of his counterparts.

Murray used his defense, and especially a piercing return of serve, to demoralize Monaco and take the sting out of the Argentine’s shots. After winning the second set and then breaking for a 2-1 lead in the third, Murray put his foot down by winning three more games in a row. Up by a 5-1 count, the Scot closed the door to advance to Monday’s third round.

Juan Monaco put up a fight, and gave Andy Murray cause to doubt himself. But with the chips on the table, the most ascendant player in men’s tennis reminded his rivals why he’s going to grab a Grand Slam in due time, barring some shocking and unforseen turn of events.

Rafael Nadal hit 13 winners and committed 17 unforced errors in Sunday afternoon’s championship match of the BNP Paribas Open.

Under normal circmstances, such a performance would have led to a decisive loss. But this was no ordinary day in the California desert, and Nadal, of course, is no ordinary player.

In the face of strong winds that varied from 15 to 30 miles per hour, Nadal was nothing short of magnificent in fighting through daunting conditions. Scotland’s Andy Murray was the unlucky student in this master class, as Nadal’s consistent precision carried the No. 1 player in the world to his second Indian Wells title with a 6-1, 6-2 victory in 80 efficient minutes. Murray had another fine tournament marked by yet another triumph over Roger Federer, but Nadal once again reminded the Scot who rules the roost in men’s tennis.

Two years ago, Nadal broke through to win his first championship at the Indian Wells Tennis Garden, which was–at that time–the biggest hardcourt trophy of the Mallorcan’s career. But with Federer owning the hardcourt slams in 2007, it seemed unlikely that Nadal would conquer the concrete surface anytime soon. Now that he’s bagged yet another title at this prestigious event, Rafa–fresh off his first hardcourt slam title in Australia–has only cemented his status as an elite player on surfaces other than clay. Nadal is a prohibitive favorite at every important tournament he enters, and this throttling of the fourth-seeded Murray showed why.

Murray, it should be said, hit only 22 unforced errors in this match. The word “only” is used because of the strong winds that wreaked havoc with both men’s groundstrokes. While it’s true that the desert gusts were even worse in the women’s title match that immediately preceded this showdown, the mortal enemy of all tennis players was still significant enough to toy with the forward motion of almost every shot. Nadal and Murray, all things considered, did extremely well to combine for fewer than 40 errors. Nadal, though, raised his “bad weather game” to an art form.

Sometimes driving his backhand through the wind for a screaming winner, and other times hitting a teasingly gentle slice that bent from the middle of the court to Murray’s forehand corner, Nadal manipulated the ball with remarkable skill, putting the Scot on the defensive and establishing a winning position on most points. Impregnable from the back and supremely artful at the net, Nadal imposed himself on Murray in all facets of play. Even though the No. 4 seed competed vigorously and fought to the bitter end, the best player on the planet always had a superior answer, particularly on the many 30-all and deuce points that characterized most of the games in the match. The quality of the rallies produced by the two men were worthy of a close 6-4, 6-4 match, but Nadal’s otherworldly composure in the midst of nasty winds allowed the Spaniard to breeze home with another title.

The ATP Tour now heads to Miami for yet another 96-player, week-and-a-half event. Murray might make his presence felt, and a fellow named Federer could bounce back, but there’s only one man who will be favored to win in South Florida, and that man’s name is Rafael Nadal.