Marin Cilic and Gael Monfils retained their slim chances of reaching next month's ATP World Tour Finals by toughing out second-round wins at the BA Trophy on Thursday.
Top-seeded Cilic beat Daniel Brands of Germany 7-6 (7), 6-4, while third-seeded Monfils overcame Jan Hajek of the Czech Republic 6-1, 2-6, 6-4.
The pair, along with second-seeded Radek Stepanek, are also vying for the last two berths in the elite, eight-man tour finals in London next month. Cilic was 12th in line, Stepanek 14th and Monfils a distant 16th.
Fellow seeds, No. 6 Feliciano Lopez, the 2004 Vienna champion, and No. 7 Jurgen Melzer, also reached the quarterfinals.
Top-seeded Cilic, looking for his third title of the season, was broken when serving for the first set at 5-4 and then saved a set point in the tiebreaker.
Cilic sealed the win on his third match point and next plays Lopez, who defeated Daniel Koellerer of Austria 6-3, 6-3 to reach his sixth quarterfinal in Vienna in as many years.
The 45th-ranked Lopez dominated most of the match, apart from struggling early in the second set when he lost serve once.
In earning his eighth quarterfinal of the season. Monfils conceded just seven points in a 17-minute opening set, but lost control afterward.
"I've got a headache, nothing serious really," the Frenchman said. "I should be OK tomorrow and play again on the same level as I did in the first set."
Monfils, who reached the final in Vienna last year, used one of seven break points to close out the match in the decider.
He will next play Janko Tipsarevic, who beat Michael Berrer of Germany 7-6 (3), 6-1.
Berrer, who replaced injured defending champion Philipp Petzschner in the main draw, was broken twice while serving for the opening set at 5-4 and 6-5.
Tipsarevic, coming off his first career final in Moscow last week, used three breaks in the second to wrap up the victory.
Austria's Melzer defeated Dominik Hrbaty of Slovakia 6-4, 7-5 and advanced to his seventh quarterfinal of the year.
Melzer meets Stepanek in the quarterfinals on Friday.
