Roger Federer beats Karen Khachanov to advance to his 11th Halle final

HALLE, Germany (AP) Roger Federer defeated Karen Khachanov 6-4, 7-6 (5) to advance to the final of the Gerry Weber Open for the 11th time on Saturday.

Chasing his ninth title at the grass-court tournament, Federer was serving for the match when he was broken by the 21-year-old Russian. Khachanov then missed two set points before Federer took it to the tiebreaker.

''It was all a little uncertain because I don't know him that well,'' said Federer. ''It's warm, it's hot, I'm a little bit tired. It was a difficult match.''

• Beyond the Baseline Podcast: Brienne Minor

Federer saved four of the six break points he faced overall, while converting three of his five opportunities.

The 35-year-old Swiss will face fourth-seeded Alexander Zverev or Richard Gasquet in Sunday's final.

Federer had a busy start to the year - winning at the Australian Open to take his 18th Grand Slam title - and his decision to skip the clay-court season to recuperate appears to be paying off with a view to Wimbledon, where he is a seven-time champion.

''Everything has been geared toward that for the past 12 months and I'm happy with how I feel at the moment,'' Federer said.