It’s surprising enough that Tommy Haas finds himself in his first Wimbledon semifinal at the age of 31. It’s far more remarkable that a tormented soul defeated his frail nerves en route to the final four at SW19.

Haas not only turned back fourth-seeded Novak Djokovic in Wednesday’s quarterfinals; the 24th-seeded German did much to dispel the demons that have followed the veteran throughout his rollercoaster career.

Haas’s 7-5, 7-6 (6), 4-6, 6-3 victory on Court No. 1 was more than a hard day’s work at a lawn-coated office. This tennis graybeard wiped away the bitter taste of collapses and letdowns that accumulated over time.

Last week, as Haas had to spend a night sleeping over a 6-all fifth-set tie in his third round match against Marin Cilic, the former world No. 2–ravaged by all sorts of injuries and the psychological strain stemming from a motorcycle accident that nearly killed his parents–had to confront the ghosts of a snake-bitten past. Haas needed to come to grips with the blown two-set leads, the failures in five-set matches, and all the obstacles that stood in the way of a career resurgence after missing all of 2003 with a rotator cuff injury. When he did beat Cilic in the resumption of that match, Haas began to write a new narrative in suburban London, and this jolting of Djokovic marked a crowning continuation of that journey.

There were two moments in this match when the old Tommy Haas would have cracked and crumbled, allowing the Serb to advance to Friday’s semifinals. The first such occasion emerged at the end of the second set, when Haas–serving for a two-set lead at 6-5–missed an easy forehand at love-15 to help Djokovic break back and force a tiebreak. That untimely error sent Haas’s mind into a familiarly dark place, and after a series of loose groundstrokes, particularly from the forehand wing, the German found himself trailing, 6-3, in the breaker. Djokovic had three set points, and what was left of Haas’s early advantage was about to be cleared off the scoreboard.

But a funny thing happened on the way to a tied tennis match: Haas transformed himself in a hurry.

Belting two huge serves to knock off the first two set points, Haas then smacked a perfect down-the-line backhand to knot the breaker at 6-all. After Djokovic–in his most costly mistake of the whole afternoon–overhit an easy forehand put-away to give Haas set point, the No. 24 seed finished an extended rally with an above-average stab volley to take the second set. In just a few precious minutes, Haas went from a free-fall into free-flowing bliss. Armed with a big advantage, the underdog didn’t have to be perfect as the third set dawned, but he did have to find a way to close down Djokovic before too long.

In the fourth set, Haas pounced when the time was right, elevating his concentration at the first whiff of opportunity.

Djokovic played a tired and distracted game in which Haas broke for a 3-1 lead. Yet, the timeless wisdom of tennis says that a break isn’t a break unless or until it’s consolidated, and when Haas stared down the barrel of a 30-30 situation later in the fourth set, his nerves would receive a test similar to the second-set tiebreak.

On that 30-all point in the fifth game of the fourth set, Djokovic flashed some superb defense, forcing Haas to retreat from a winning position and choose between hitting an overhead or a traditional forehand from just inside the baseline. Haas chose to hit the overhead, a risky decision given the low margin for error on the shot. In the past, Haas would almost certainly have netted the ball, but on this day, the new-look German blotted out the gremlins and goblins that had bedeviled him once upon a time. Haas nailed the overhead to win the point and eventually hold for 4-1. Djokovic’s last, best hope for a comeback evaporated, and when Haas used some heavy, high-kicking second serves to fight through his final service game, the semifinal berth had been securely tucked away. Not bad for an old man who had never reached the semis at a major tournament other than the Australian Open.

While Djokovic will curse his subpar return of serve, and lament his inability to push past the quarterfinal round of a slam (the Serb has made just one semifinal in his past five majors), a 31-year-old with a lifetime’s worth of upheavals will rightly celebrate a special achievement that is magnified by its long-delayed nature.

Tommy Haas has been fleeing from his demons for years. On Wednesday, in the Wimbledon quarterfinals, he finally decided to chase them away. Roger Federer and Andy Murray might be the odds-on favorites at the All England Club, but when Semifinal Friday commences, it’s Haas who offers a winning story, a tale of perseverance in the face of life’s countless curveballs and absurdities.