WATCH: Taylor Fritz loses his shoe, and then the match, against Alexander Shevchenko in Basel

Taylor Fritz could only shake his head and throw his hands up in disbelief, after tripping up (literally) during a crucial moment of his marathon three-set battle against Alexander Shevchenko at Swiss Indoors Basel.

The American already had two match points earlier in the third set, but saw both erased by two monster forehands from Shevchenko. The world No. 83, who defeated Stan Wawrinka in the first round and Fabio Fognini during qualifying, was playing the best tennis of his life against Fritz—refusing to fade away as the match approached the three-hour mark.

In fact, Shevchenko had Fritz running so hard side to side that the American literally lost his shoe when changing direction to chase down a drop shot near the net during the third-set tiebreaker. (Video above)

“He (Fritz) wasn’t sure where to put himself, and as he tries to push off he loses his shoe!” said commentator Lucie Ahl, as cameras caught Fritz laying on the floor laughing in disbelief. “That’s certainly not going to help, is it?”

And indeed it proved to be a bad omen: The Russian soon completed the upset, toppling the world No. 9 in a marathon 6-7 (7), 7-6 (6), 7-6 (5) contest to reach the quarterfinals in Basel after two hours and 55 minutes.

“Tennis is rough,” was all Fritz had to say on social media afterwards, as commiserations began pouring in on X. Fritz struck a whopping 61 winners and 21 unforced errors, won 10 more points than his opponent (139 to 129) and created 15 break opportunities—but to no avail.

For Shevchenko—who saved all 15 of those break points, including two match points—Thursday’s victory marks his first Top 10 win and biggest win of his career to date. He will face either Botic van de Zandschulp or Felix Auger-Aliassime next, as he seeks first ATP semifinal.

But for Fritz, who was hoping to boost his chances to qualify for the Nitto ATP Finals, it’s back to the drawing board. The American currently sits at No. 9 on the Race to Turin, and had been targeting the crucial No. 8 spot occupied by Holger Rune—the Dane faces Sebastian Baez in Basel later in the day.

The first five ATP Finals spots have already been locked in, with Andrey Rublev becoming the latest to qualify on Thursday. He will join Novak Djokovic, Carlos Alcaraz, Daniil Medvedev and Jannik Sinner at the season-ending event, leaving just three spots at stake with less than three weeks to go.