Roger Federer beats Ivo Karlovic to reach Gerry Weber Open final
World number two Roger Federer eased into the Gerry Weber Open final with a straight-set victory over Ivo Karlovic.
The Swiss top seed won 7-6 (7-3) 7-6 (7-4) to move closer to a record eighth title in Halle, Germany.
Karlovic, 36, hit 45 aces - the most in a three-set ATP Tour match - against Tomas Berdych in the last eight.
Federer, 33, was unable to secure a single break point against the Croat but won both tie-breaks to set up his 10th appearance in the event's final.
A brilliant backhand return followed by a Karlovic double fault secured Federer the first set and he went on to seal victory after one hour and 28 minutes with a backhand volley in the second tie-break.
"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 tie-break."
Federer will meet Italy's Andreas Seppi in Sunday's final after second seed Kei Nishikori retired early with a calf injury after the fifth game of the other semi-final.
The 25-year-old world number five, who was trailing 4-1 when he retired, said: "I felt it yesterday during the quarter-final and I fought through it.
"But there was a little pain this morning and I tried in the match, but couldn't really move.
"I don't want to take a big risk for Wimbledon."