Roger Federer moved into the quarter-finals of the ATP Swiss Indoors on Wednesday, although he was given a stern test by Jarkko Nieminen before progressing.
Defending champion Federer, who is ranked three at the event this year, needed three sets before finally seeing off his resilient Finnish opponent 6-1 4-6 6-3.
It was the first time in their 12 meetings that Federer has surrendered a set to Nieminen, but the 16-time grand slam winner was happy enough with his performance.
"It was still a good match, I thought, for me to come through," stated Federer, who served three straight double faults when broken in the second set.
"It was due to my ups and downs that he got a chance."
With Andy Murray having earlier pulled out of the tournament with a muscle strain, Federer now appears to have an easier path to a possible final showdown with top seed Novak Djokovic.
However, the Swiss was quick to insist he was not looking beyond his next match.
"I never saw (Murray) as a potential opponent anyway because I'm too focused on what I have to do," he added.
"I am sure it is somewhat disappointing for the tournament director after going through all the headaches with the wild cards."
Like Mardy Fish on Tuesday, sixth seed Janko Tipsarevic retired hurt during his first-round match.
Tipsarevic found himself 5-1 down in the first set when opted to call time on his contest with Florian Mayer of Germany.
The Serb will now have to reach at least the final in next week's Paris Masters if he's to qualify for the eight-man ATP World Tour Finals in London.
Andy Roddick produced a strong serving display to clinch a routine 6-3 6-4 victory over Tommy Haas of Germany - the seventh seed sent down 12 aces and did not give up a single break point chance.
Roddick will now face Radek Stepanek of the Czech Republic who won 6-1 6-3 against Santiago Giraldo of Colombia.
Injured Murray's place was taken by lucky loser Marco Chiudinelli, a childhood friend of Federer, who lost 6-2 7-6 (9-7) to Robin Haase of Holland.
Elsewhere, Lukasz Kubot of Poland beat Tobias Kamke of Germany 5-7 7-5 6-2 and Marcos Baghdatis advanced to the quarter-finals by defeating 327th-ranked Swiss qualifier Michael Lammer 7-6 (7-2) 6-7 (7-2) 6-3.