Stan Wawrinka made it through his test with Daniel Evans at the Indian Wells Masters, while Australian teenager Alexei Popyrin claimed his first ATP 1000 victory.
Wawrinka recovered after losing the first set against Evans as the Swiss veteran reached the second round on Friday.
Popyrin joined the three-time grand slam champion in the next round following his breakthrough win over Jaume Munar.
Australian Open quarter-finalist Frances Tiafoe, meanwhile, was sent packing along with Tomas Berdych.
Wawrinka survives first-round scare
Runner-up in 2017, Wawrinka rallied past Englishman Evans 6-7 (4-7) 6-3 6-3 on Stadium 2.
Wawrinka had to produce his best tennis in the first round after reeling off five straight points at 2-2 and 0-40 to hold serve.
He saved another three break points at 3-3 before racing out to a 5-3 lead and never looking back.
"I like the tournament," said Wawrinka, who will face 29th seed Marton Fucsovics in the next round. "I think in general the conditions are good for my game. A hard court and quite slow, I would say. You can really play your game. I think for me this year it's for sure special because I'm happy to be back."
Popyrin earns Isner clash
The 19-year-old recorded his first ATP 1000 victory by defeating Munar 7-6 (9-7) 6-3 on Friday.
World number 131 Popyrin, who stunned Dominic Thiem at the Australian Open, will meet eighth seed John Isner in the second round.
"It definitely means a lot," said Popyrin. "Growing up watching these tournaments on TV, just to get my first Masters 1000 win is a great achievement for me."
Tiafoe says goodbye
Despite saving two match points, Tiafoe went down to Nicolas Jarry 6-4 4-6 7-5 in the opening round.
Down 5-4 in the third set, Tiafoe fended off a pair of match points to stay alive, but the American was unable to stop Indian Wells debutant Jarry.
Berdych, meanwhile, lost 7-6 (7-3) 7-6 (7-2) to fellow veteran Feliciano Lopez.