French qualifier Gregoire Berrere weathered storms on and off the court to beat two-time champion John Isner 6-7 (3) 7-6 (5) 6-3 in the first round of the ASB Classic in New Zealand.
Matches were moved indoors on Tuesday as tropical Cyclone Hale battered Auckland with gale-force winds and rain.
The move suited Berrere who considers indoor hardcourts his best surface.
Berrere also had to endure the American's powerful serves. Isner had 28 aces but Berrere was patient and prevailed.
Isner is 12 aces away from becoming the first player to serve 14,000 aces in ATP Tour and Grand Slam events.
The win was Berrere's first in 23 attempts against a top-50 opponent. Isner currently is ranked 37, off his career high of No.8 in 2016.
"I'm feeling good, actually I'm feeling great," Berrere said. "I trained a lot last week because I lost in the first round of my last tournament so I tried to prepare for this tournament."
Berrere knew the challenge of playing Isner and prepared himself, concentrating on his return of serve.
He produced the crucial play of the match when he struck a cross-court winner from Isner's second serve for 5-3 in the deciding set.
Berrere then comfortably held serve to take the match in just over two hours, and will face compatriot Constant Lestienne in the second round.
American Chris Eubanks, also a qualifier, beat defending champion Ugo Umbert 7-6 (5) 7-6 (3).
The 26-year-old Eubanks also wields a powerful serve and stuck with Humbert through a tight match before taking a decisive 6-1 lead early in the second set tiebreaker.
Earlier, American Marcos Giron rallied from a set down to beat Federico Coria of Argentina 6-7 (5) 6-4 7-5.