VIENNA (AP) Ivo Karlovic advanced to his 10th quarterfinal of the season by defeating Sergiy Stakhovsky of Ukraine 6-4, 7-5 at the Erste Bank Open on Wednesday.
The seventh-seeded Croat avoided break points in the second-round match and conceded just nine points in his 11 service games.
Karlovic next plays Ernests Gulbis. The 117th-ranked Latvian, who was on a five-match losing streak coming to this tournament, upset third-seeded John Isner 6-4, 4-6, 6-4 to reach his third quarterfinal of the year.
In a match dominated by strong serving, Gulbis hit 23 aces against the American's 16. Each set was decided by one break though both players had to fight off six break points.
In first-round play, second-seeded Kevin Anderson of South Africa dropped just seven points on serve while defeating the last Austrian left in the tournament, Andreas Haider-Maurer, 6-4, 7-5.
It's the first time in 33 years that no Austrian player has made it past the opening round of their home event.
Also, fourth-seeded Jo-Wilfried Tsonga beat Tommy Haas 6-3, 6-7 (3), 6-4 in a match between two former champions.
Tsonga, the 2011 winner, came within two points of victory when he led 6-5 in the second set. The Frenchman conceded just four points on his serve in the final set against the German, who won the title here two years ago.
Eighth-seeded Fabio Fognini also advanced to the second round after beating Paul-Henri Mathieu of France 6-4, 3-6, 6-3. The Italian was a break down in the final set before winning the last four games.