A brief rain delay in the first game was barely a blip for Denmark's Holger Rune in a 6-4, 6-4 victory over in-form Greek Stefanos Tsitsipas on Tuesday at Indian Wells..
Tsitsipas was coming off his first title in nearly a year in Dubai last month, but Rune, ranked 13th, snapped the world No 9's seven-match ATP win streak with an aggressive game that included 22 winners.
Up 4-3 in the second set, Rune saved a break point with a dazzling between-the-legs shot, racing back to the baseline after a Tsitsipas lob and batting the tweener that dropped perfectly to deny the Greek.
"The tweener – that's the first thing I’m going to check when I get back to my phone," Rune said.
Rune, 21, has struggled since his fourth-round run at the Australian Open, but he improved his record against Tsitsipas to 4-0.
MENTALLY VERY GOOD
"Mentally, I was very, very good," Rune said. "I think that's what made the difference – how composed I was able to stay. Obviously Stef is back in shape, so yeah, it was a cool battle."
Rune next faces 43rd-ranked Tallon Griekspoor, who upset top seed Alexander Zverev in the second round.
Griekspoor also made a belated start and waited out a second-set delay in his 7-6 (7/4) 6-1 victory over Japanese qualifier Yosuke Watanuki and women's world No 4 Jessica Pegula and Elina Svitolina were one game into their third set when play was halted again.
World No 6 Daniil Medvedev was scheduled to open the night session against American Tommy Paul in a rematch of their semifinal last year.
Russia's Medvedev won that match to reach his second straight Indian Wells final, where he lost to Carlos Alcaraz for the second year in a row.
Paul is one of five US men in the fourth round. Among them unseeded Marcos Giron was also in action on Tuesday taking on 20th seed Arthur Fils of France.