UMAG, Croatia -- Andreas Seppi of Italy advanced to the quarterfinals of the Croatia Open when Andreas Haider-Mauer retired with an injury while trailing 6-1, 4-0 on Thursday.
Haider-Mauer started well, winning the opening game, but then lost 10 straight games. He sought medical treatment for a lower back injury after the first set and retired in the second.
Horacio Zeballos from Argentina also advanced after rallying to defeat eighth-seeded Carlos Berlocq 3-6, 6-3, 6-2. Tommy Robredo won in straight sets to reach the quarterfinals, defeating Viktor Toricki 6-0, 6-4
Seppi is making his fourth appearance in the quarterfinals at Umag in as many years. He improved to 9-3, with his best result the semifinals in 2009 and 2010 -- when he lost both times to Spain's Juan Carlos Ferrero.
Dolgopolov, who won this event in 2011, struggled to keep up. Bedene, currently ranked 100th, won nine out of 10 games after a 2-2 tie in the first set.
Umag will be the second quarterfinal of the year for Bedene, who was a semifinalist in Chennai in the opening week of the season.