Daniil Medvedev shook off a mid-match ankle injury to reach the Indian Wells quarter-finals with a gutsy 6-7(5), 7-6(5), 7-5 win over Germany's Alexander Zverev on Tuesday, extending his winning streak to 17 matches.
It was an impressive effort from the fifth-seeded Russian whose tournament appeared over when he crashed to the court in the second set with what looked to be a serious injury.
Medvedev was able to continue and advance to the last eight for the first time but he said he expected to feel considerable pain and would likely have a scan to assess the damage.
"Now when the adrenaline goes down the body cools down it's going to be pretty painful and I'm going to probably do a scan to see what it is and if I can continue to play," said Medvedev, winner of three straight events in Rotterdam, Doha and Dubai.
Down a set and on serve at 3-2 in the second, Medvedev turned over his ankle attempting to make a return and winced in pain as the trainers, Zverev and the tournament supervisor all rushed to his side as he clutched his right leg.
Once back in his chair, Medvedev had the ankle heavily taped and returned to the court hobbling, but determinedly forcing the second set to another tiebreak.
This time, the 27-year-old Russian prevailed 7-5 to send the contest to a third set.
"When I twisted it I thought I'm going to stand up just fine and then the pain started growing very fast and I thought, 'Oh, that's not a good sign,'" Medvedev said.
"I felt like I didn't break it but I thought maybe one of the ligaments is a little injured so I thought I wasn't going to be able to play.
"That is one of the first times in my life where the physio taped my ankle, so I decided to give it a try and what was very surprising (was that) it was much easier to run than to walk."
Medvedev carried his build up of momentum into the third set, snatching the early break to go up 2-1.
With Medvedev serving for the match at 5-4, 12th seed Zverev secured his second break in 17 chances to extend the contest.
But the German handed Medvedev the advantage right back by double-faulting to gift his opponent another break and a 6-5 lead.
Medvedev did not waste a second opportunity to close out the three-hour, 15-minute contest, taking the game to love when Zverev sent his return wide.
Medvedev said he planned to tape the ankle and take a painkiller to be good to go when he faces Spain's Alejandro Davidovich Fokina in his quarter-final on Wednesday.
Fokina beat Chile's Cristian Garin 6-3, 6-4 on Tuesday.
FRITZ DIGS DEEP
Defending champion Taylor Fritz dug deep into his arsenal to beat Hungarian Marton Fucsovics 6-4, 6-3 to reach the quarters.
Leading 2-0 in the second set, the American closed out a marathon game when he hit a reverse serve - a shot that appears to be going down the tee but is instead directed toward the right-handed opponent's backhand.
The trick shot did just enough to throw the hard-hitting Fucsovics off, as the point and the game ended when the Hungarian sent a forehand out wide.
Fritz next faces Jannik Sinner, who beat Swiss veteran Stan Wawrinka 6-1, 6-4 to reach the last eight for the first time.
Elsewhere, 10th-seeded Briton Cameron Norrie upset sixth-seeded Andrey Rublev of Russia 6-2, 6-4 and American Frances Tiafoe was a 6-4, 6-4 winner over Chilean Alejandro Tabilo.
Top seed Carlos Alcaraz also went through after his ailing opponent Jack Draper retired while trailing 6-2, 2-0.
The world number two faces Felix Auger-Aliassime, who rallied from a set down and saved six match points to beat Tommy Paul 3-6, 6-3, 7-6(6).
"I always stayed positive, kept my hopes up, kept thinking 'OK, I'm not that far, I can come back,'" Auger-Aliassime said.
"At the end, when you're down 0-40 on your serve, you know that... 'OK if I win this first one, serve well, then again, then again, we're back on even terms.'
"You just kind of take it one by one. It's very cliched to say but it still works; that's the proof. I'm really happy to get through. It's a crazy feeling."