NEWPORT, R.I. (AP) Peter Gojowczyk upset defending champion Ivo Karlovic 7-6 (5), 6-7 (1), 7-6 (4) on Thursday to reach Hall of Fame Tennis Championships semifinals.
Gojowczyk, a 28-year-old German, overcame 30 aces from the second-seeded Croatian. Gojowczyk was 3 for 3 on break points.
''In the end, it didn't go my way,'' Karlovic said. ''That's life, that's tennis. That's how it goes sometimes.''
Gojowczyk will face Australia's Matthew Ebden, a 4-6, 7-6 (6), 6-4 winner over Germany's Tobias Kamke. Ebden is the first qualifier to reach the semis on Newport's grass courts since 2011.
Ebden upset sixth-seeded Lukas Lacko in the second round.
The other quarterfinal matches are Friday. Top-seeded John Isner, the big-serving American who won the tournament in 2011 and 2012, will play fellow countryman Dennis Novikov. No. 4 Pierre-Hugues Herbert of France will face American Bjorn Fratangelo.