Kei Nishikori defeated Steve Johnson 6-1, 7-6 (7-4) on Friday to reach the semifinals of the Gerry Weber Open.
Nishikori made short work of the first set, but remained on-serve through the second set despite three break chances. Nishikori won the tiebreaker for a straight-sets victory.
"I had a good serve," said Nishikori, who faces Roger Federer next.
"I'm playing with confidence. I had a solid start, and I was able to raise the level of my game to take the tiebreaker in the second set. I'll have to prepare my tactics when I face Roger since he is great on grass."