Roger Federer beats Frances Tiafoe on return to Miami Open
Roger Federer beat American teenager Frances Tiafoe in his first match at the Miami Open for three years.
The Swiss, 35, defeated the 19-year-old qualifier 7-6 (7-2) 6-3 to take his 2017 record to 14 wins and one loss.
Federer, who won has won the Australian Open and Indian Wells titles this year, missed Miami through illness in 2016.
Top seed Stan Wawrinka beat Horacio Zeballos 6-3 6-4, while women's fifth seed Agnieszka Radwanska was thrashed 6-0 6-3 by Mirjana Lucic-Baroni.
"It's quite tough conditions, raining and really windy today," Swiss Wawrinka said.
"It's really windy on the court, so it's never easy. I'm happy with the way I was moving, the way I was playing and my attitude in general was really positive, so it's a great match."
Federer picked up where he left off in Indian Wells, winning his first 20 service points on the way to overcoming an impressive effort from Tiafoe, the world number 101.
"I've hit with Frances maybe twice before," Federer said.
"I saw the power he had, the explosivity he had, how he easily can generate pace. He seemed to be fearless, good serving, taking the ball early and making the plays.
"What I like to see is when a younger player comes out and really feels he has nothing to lose and only has stuff to gain."
Next up for Federer is Juan Martin del Potro, who beat Dutchman Robin Haase 6-2 6-4.
Federer has a 15-5 career record against Argentina's Del Potro, the 2009 US Open champion.
"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."
Warning for Kyrgios
Australian Nick Kyrgios won his match, and also received a code violation warning from the chair umpire for swearing at a spectator who called out during a point.
Kyrgios, the 12th seed, dropped his first two service games, but fought back to beat Damir Dzumhur 6-4 6-3.
Austrian sixth seed Dominic Thiem lost 6-1 7-5 to 20-year-old Croat Borna Coric, but Belgian eighth seed David Goffin beat Darian King of Barbados 7-5 6-1, and Czech 10th seed Tomas Berdych overcame Russia's Andrey Rublev 6-3 6-2.
In the women's draw, Croatian 26th seed Lucic-Baroni needed just 20 minutes to win the opening set as she swept past Poland's Radwanska.
Spanish sixth seed Garbine Muguruza came through a tough test to beat China's Zhang Shuai 4-6 6-2 6-2.
Karolina Pliskova, the Czech second seed, beat Kazak 27th seed Yulia Putintseva 7-5 6-3.
In the men's doubles, fourth seeds Jamie Murray and Bruno Soares beat Treat Huey and Max Mirnyi 6-4 6-3.