Vienna - Janko Tipsarevic reached his 13th quarter-final of the season by defeating Ernests Gulbis of Latvia 6-3, 6-4 at the Erste Bank Open on Thursday.
The ninth-ranked Serb, who is looking to qualify for the season-ending ATP World Tour Finals, dropped serve once in each set but dominated play from the baseline against Gulbis.
"I have to be pumped for every single point and not think what's going on behind me or ahead of me," Tipsarevic said. "The only thing I care about now is winning my next match. I don't think about winning the tournament or about reaching London."
Tipsarevic said his changed attitude towards the game has helped him to become a consistent top-10 player this year.
"I don't feel I improved my forehand, backhand or serve dramatically," he said. "I just feel that now I am living and breathing tennis outside of the tennis court as much as I am on the tennis court... This changed after winning the Davis Cup. I realised I wasn't getting any younger and that I would regret it if I realised one day that I could have reached more in my career."
Tipsarevic, seeded second, next plays Aljaz Bedene of Slovenia in the quarter-finals. Bedene defeated Donald Young of the United States 7-6 (7/4), 6-7 (2/7), 6-3.
Marinko Matosevic of Australia defeated wildcard Dominic Thiem of Austria 6-3, 7-6 (7/5) to set up a quarter-final against top-seeded Juan Martin del Potro.
The 55th-ranked Matosevic, who was on a six-match losing streak before the event, held serve throughout. Thiem, ranked 394th, had eight aces but missed out on his first career quarter-final.
In other second-round play, Grega Zamlja of Slovenia beat Matthew Ebden of Australia 7-5, 6-4; and Paolo Lorenzi of Italy defeated Vasek Posposil of Canada 6-4, 6-4.