No. 17 seed Arthur Fils delivered 25 winners and overcame back pain to deliver a 3-6, 6-3, 6-4 upset of top-seeded Alexander Zverev on Wednesday to reach the Miami Open quarterfinals.

The 20-year-old Frenchman recovered from the first-set loss to defeat Zverev for the second time in the past three meetings.

Fils said he has been dealing with fierce back pain and persevered after digging the early hole.

“In the first set, I was not playing great,” said Fils, who had four aces. “I found a way today, I was so lucky late in the match.”

After losing the opening set, Fils jumped out to a 3-0 lead in the second en route to evening the match.

Zverev took a 3-1 lead in the third set before Fils won the next four games. After Zverev won the next game, Fils closed out the match.

“In the third set I thought it was over, at 1-3 and with him serving great,” Fils said. “I just said, ‘OK, don’t get mad. Just try to play as much as you can and try to fight, and if you get a break, it’s nice.’ It happened, so what can I say.”

Zverev had nine aces but the German finished with just 14 winners.

Fils will face Jakub Mensik of the Czech Republic in Thursday’s quarterfinals.

–Field Level Media