Roger Federer remained on course for back-to-back Masters titles as he beat Spain’s Roberto Bautista Agut in straight sets to enter the quarter-finals of the Miami Open. Federer claimed his 25th Masters title at Indian Wells over a week ago. He beat Bautista 7-6 (5), 7-6 (4) and will now face a stern tern in Tomas Berdych.

Asked if this was the best he had ever played, Federer said, “For me, it’s hard to say yes to that question. Maybe on the offensive side, overall, I think I’m doing definitely a few things better than I ever have. I do feel that I have improved. The game has evolved, I had to adjust, but overall I do believe I’m probably a better player than I was 10 years ago.”

Wawrinka stunned

Stan Wawrinka, the top seed at Miami, was beaten by teenager Alexander Zverev on his 32nd birthday. Wawrinka lost 4-6, 6-2, 6-1 as Zverev set up a clash with none other than Australian sensation Nick Kyrgios, who beat David Goffin 7-6(5), 6-3.

“One bad game to start the second set and then it was tough for me,” Wawrinka was quoted as saying. “I completely went down physically and mentally, and also my tennis was completely out. I had no more gas.”

Zverev, who played more aggressively after losing the first set, said that it was part of his game plan. “I had to be aggressive. I felt like he was the one controlling all the points all the time, so I had to change that. It worked out well for me,” Zverev said.

Nadal progresses

Rafael Nadal continued his dominant run as well as he beat Nicolas Mahut 6-4, 7-6 (4) to set-up a quarter-final clash with Jack Sock. Addressing the resurgence of both him and Federer this season, Nadal said, “It’s a good start of the year, I think, for both of us. Obviously, it’s a little bit better for him, but at the same time I’m happy with the way that I am playing, happy with the way that I started the year after a tough second part of the year last year with injuries. So I think it’s a positive for both of us that we can still (be) around here and be very competitive almost every week that we are playing.” Federer has beaten Nadal in the last three occasions the two have clashed.

Miami Open: Quarter-final line-up (men’s)

Alexander Zverev (16) v Nick Kyrgios

Roger Federer (4) v Tomas Berdych (10)

Rafael Nadal (5) v Jack Sock (13)

Fabio Fognini v Kei Nishikori (2)