Federer into 15th Halle quarters

Eight-time champion Roger Federer reached the quarterfinals of the Halle grasscourt tournament for a 15th time on Thursday with a 7-6 (4), 6-4 win over German serve-and-volleyer Mischa Zverev.

Federer, the 18-time Grand Slam title winner who is building up for an assault on an eighth Wimbledon title next month, next faces defending champion Florian Mayer for a place in the semifinals.

The 134th-ranked Zverev made the quarterfinals by seeing off French sixth seed Lucas Pouille 6-7 (6), 6-4, 6-3.

Federer now has a 4-0 record against Zverev, including a win this year in the quarterfinals of the Australian Open.