Roger Federer reached the semi-finals of the Swiss Indoors tournament on Friday after a stuttering 6-3, 7-6 win over Spanish fifth seed David Ferrer.
Still seeking his first title in his home town, the world number one began badly, dropping serve in the opening game, but had a lucky reprieve when Ferrer double-faulted twice in the following game to restore a nervy equilibrium.
Breaks of the Spaniard's serve late in the first set and early in the second seemed to hand Federer control but the Swiss suffered an uncharacteristic wobble as he dropped serve again with a couple of unforced errors to leave the second set at 4-4.
The subsequent tiebreak was a close affair, with Ferrer looking likeliest to break the deadlock.
Further errors by both players saw the Spaniard fail to convert six set points and Federer missing three match points before finally taking the tiebreak 16-14 when Ferrer slammed the ball into the net.
Federer will now meet Paradorn Srichaphan in the last four, following the unseeded Thai's 7-6, 6-3 win over Argentine seventh seed Jose Acasuso.
RISK
"I think I was trying to risk a bit more in front of my home crowd today, so I'm just lucky that it paid off in the end," said Federer.
"It's been a while since I dropped serve at the start of a match, so it was important that I reacted well."
The Swiss fans had double reason to cheer as Federer's Davis Cup team mate Stanislas Wawrinka also booked a semi-final spot with a shock win over Argentine second seed David Nalbandian.
Having spent much of the week in the shadows of the world number one, the Swiss number two got a share of the limelight with a blistering 7-6, 6-2 win over the world number three.
Wawrinka, who won his first ATP title at Umag earlier this season, served impressively throughout the opening set but squandered five opportunities to break his opponent's serve.
Those missed chances could have proved costly in the subsequent tiebreak when Nalbandian twice broke ahead, but each time the young Swiss was able to draw level.
After defending one set point and missing one of his own, Wawrinka had another chance when Nalbandian overhit a baseline shot. This time Wawrinka converted successfully with an ace.
ONE-SIDED
The second set was surprisingly one-sided with Wawrinka racing into a 4-0 lead before comfortably serving out for the match.
"Today was probably the best win of my career and it would be a dream to play Roger in Sunday's final but for now I just want to concentrate on the semis," said Wawrinka.
He now meets defending champion Fernando Gonzalez after the Chilean world number seven came through his third three-set encounter of the week.
"I'm feeling pretty tired," said Gonzalez after seeing off Argentine wild card Juan Martin Del Potro 5-7, 6-4, 6-4 and staying in contention for a third successive final appearance.
"I played five matches in Vienna and in Madrid and it doesn't help that I had so little time to adapt to the court here... but I'm feeling better every day and the hope of qualifying for the Masters Cup is also giving me motivation."
