Nick Kyrgios was warned for an audible obscenity before roaring into the third round of the Miami Open with a straight-sets demolition of Damir Dzumhur.
In his first match since food poisoning ended his run to the quarter-finals in Indian Wells, Kyrgios dropped his first two service games before seizing control en route to a 6-4 6-3 win over Bosnian Dzumhur on Saturday Sunday (AEDT).
Australia's 12th seed next faces Ivo Karlovic, who broke a five-match losing streak with a 7-6 (7-4) 6-1 victory over Andrey Kuznetsov.
Kyrgios' second-round win wasn't without incident.
He received a code violation from chair umpire Fergus Murphy for swearing at a spectator, who called out during a point.
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But Kyrgios, last year's semi-finalist, regained his composure to comfortably advance and improve his record in 2017 to 11-3.
Meanwhile, Roger Federer won his first at the tournament after a two-year absence, beating 19-year-old American qualifier Frances Tiafoe 7-6 (7-2) 6-3.
Federer took the lead with a flawless tiebreaker after both players held easily throughout the first set, and Tiafoe then became more inconsistent with his ground strokes.
The resurgent Federer won at Key Biscayne in 2005 and 2006, and is among the favourites this year.
He is 14-1 in 2017, including his 18th grand slam title at the Australian Open and a title at Indian Wells last week.
Next up for Federer is Juan Martin del Potro, who beat Dutchman Robin Haase 6-2 6-4 in a night match.
"I would love to play against (del Potro)," Federer said, speaking before knowing who his next opponent would be.
"We've had some epic matches against each other. I'm sure the crowd would love to see it."
Federer's fellow Swiss Stan Wawrinka, seeded No.1 in an ATP Masters 1000 tournament for the first time, easily won his opening match against Horacio Zeballos 6-3 6-4.
Wawrinka lost only 13 points in his 10 service games, in amatch that lasted 65 minutes.
"I'm really happy with the match today," the Indian Wells finalist Wawrinka told reporters.
"It's quite tough conditions, raining and really windy today. It's really windy on the court, so it's never easy."
Eighth seed David Goffin and 10th seed Tomas Berdych also advanced.
Belgium's Goffin stopped Darian King of Barbados 7-5 6-1 and Czech Berdych cruised past Russia's Andrey Rublev 6-3 6-2.
Dominic Thiem, the sixth seed, fell to 20-year-old Croatian Borna Coric 6-1 7-5.
Other second-round winners were 14th seed Roberto Bautista Agut, 16th seed Alexander Zverev, 18th seed John Isner, 22nd seed Sam Querrey, 24th seed Gilles Muller, Argentina's Diego Schwartzman, Tunisian Malek Jaziri and Frenchman Adrian Mannarino.
