Roger Federer took his 2017 record to 15 wins from 16 matches as he beat Juan Martin del Potro at the Miami Open.
The Swiss, 35, won 6-3 6-4 to reach the last 16, where he will face Spanish 14th seed Roberto Bautista Agut.
“I feel like I earned it more,” said Federer, the champion in 2005 and 2006. “I was more the aggressor. It was more my racket, and I like it that way.”