Federer reaches his 10th Gerry Weber Open final

HALLE, Germany (AP) Seven-time champion Roger Federer advanced to his 10th final at the Gerry Weber Open where he will play Italy's Andreas Seppi.

Federer defeated big-serving Ivo Karlovic 7-6 (3), 7-6 (4) Saturday while Seppi won the other semifinal after second-seeded Kei Nishikori pulled out injured when the Italian was leading 4-1.

The Japanese player had his lower left leg bandaged and was in clear discomfort.

Seppi also had a short quarterfinal on Friday when fourth-seeded Gael Monfils pulled out with a right knee injury when Seppi led 6-1, 1-0.

In contrast to Federer, Seppi was playing his first semifinal in his sixth appearance at Halle.

Federer won just five points on Karlovic's serve in the first set but made a mini-break to go 4-3 up in the first tiebreaker. He won the set on Karlovic's double-fault.

In the second tiebreaker, Federer correctly challenged a call that would have put Karlovic ahead 4-3 and secured another mini-break when Karlovic hit a return into the net. He took the first of two match points to wrap up the match in 1 hour, 28 minutes.

''I'm relieved to have got through the match. It was always my aim to defend the title,'' said Federer, who will be going for his third straight at Halle on Sunday.

Karlovic was not broken all week and the eighth-seeded Croat hit 45 aces in Friday's quarterfinals, an ATP record for a best-of-three-sets match.

He had 20 aces on Saturday but couldn't prevent Federer from moving a step closer to claiming his 15th title on grass.

''Sometimes you can't do anything,'' Federer said of Karlovic's serve. ''You have to hope for a bit of luck or that you don't make a mistake at an important moment. The whole match can change in a moment. Thankfully it went well, though I had a bit of luck in the tiebreak.''

Federer's only losses in the final at Halle came against Lleyton Hewitt in 2010 and Tommy Haas in 2012.