KITZBUEHEL, Austria (AP) Top-seeded Dominic Thiem extended his winning streak to nine matches by defeating fellow Austrian Andreas Haider-Maurer 1-6, 7-6 (6), 6-4 in the second round of the Generali Open on Wednesday.
Thiem, who has won two titles in the last two weeks and climbed to a career-high 21st in the ATP rankings, went 4-1 down in the final set but won the last five games.
''Andreas played so well. I had an awful start in the match and there was a lot of luck involved,'' said Thiem, who plays Albert Montanes of Spain in the quarterfinals.
Montanes, who entered the main draw as a lucky loser after Italy's Simon Bolelli pulled out injured, beat Diego Schwartzmann of Argentina 6-1, 6-3.
Dusan Lajovic of Serbia advanced after his opponent Andreas Seppi pulled out in the second set. The second-seeded Italian trailed 7-5, 3-0 when he quit the match with back problems.
Lajovic's next opponent is Nicolas Almagro of Spain, who rallied from 5-1 down in the opening set to beat Jurgen Melzer of Austria 7-6 (4), 7-5.
Earlier, Fabio Fognini of Italy and Philipp Kohlschreiber of Germany earned straight-set wins in less than an hour to set up a quarterfinal.
The third-seeded Fognini, who lost to Rafael Nadal in the final at Hamburg on Sunday, downed wild card Dennis Novak 6-1, 6-2 in the Austrian's third match at ATP level.
Kohlschreiber, seeded sixth, eased past Santiago Giraldo of Colombia, 6-0, 6-2.
Also, French qualifier Paul-Henri Mathieu defeated fourth-seeded Martin Klizan of Slovakia 6-3, 7-5, and will next play Federico Delbonis of Argentina, who rallied to beat two-time former champion Robin Haase of the Netherlands 4-6, 6-2, 6-2.