American fourth seed James Blake kept his Masters Cup qualifying chances intact after fighting back to avoid a first round Swiss Indoors defeat against unseeded German Nicolas Kiefer on Wednesday.
Blake, currently tenth in the race for the eight-field season-ender with three places still up for grabs, lost the opening set but rallied with a break in each of the successive sets to win 3-6, 6-3, 6-4.
The win also saw the American avenge his only previous defeat to Kiefer in the quarter-finals of this year's Canada Masters Series.
"I was happy with my performance because it's always tough facing guys like Nicolas early on in a tournament," Blake told reporters.
"As far as the Masters Cup goes, I've been in similarly tight positions the last couple of years. So I'm hoping my experience will help me but I won't be looking at the points until the week is over."
The world number 11 now faces Spanish world number 76 Oscar Hernandez for a place in the quarter-finals.
Blake's compatriot and tournament eighth seed Mardy Fish fared less well -- losing his second round meeting with Spaniard Feliciano Lopez 7-6, 6-4.
Fish, who was on course for a potential quarter-final meeting with Blake, lost 11-9 in the tiebreak before suffering a single break of serve in the second set.
Russian sixth seed Igor Andreev also faced a tough second round encounter, eventually beating Germany's Philipp Kohlschreiber 7-6, 6-7, 7-5 to reach the last eight.
Finland's Jarkko Nieminen won his first round match against Argentine Eduardo Schwank to set up a second round meeting with Basel-born world number two Roger Federer.
Thursday's encounter will be a re-match of last year's final which saw Federer win his home tournament for a second successive year with a 6-3, 6-4 victory over the Finn.