Top seed Roger Federer had to fight off two match points before squeezing past Juan Carlos Ferrero 4-6, 6-3, 7-6 to reach the quarter-finals of the Dubai Open in Dubai on Thursday.
The defending champion and world number one took two hours 15 minutes to earn his victory, saving match points at 6-4 in the tiebreak before claiming it 8-6.
It was the third consecutive match in which Federer has been taken to a final set tiebreak, coming after his win in the Rotterdam final last week and his struggle against Czech qualifier Ivo Minar in the first round in Dubai.
"I definitely had a slow start again, the same as the last couple of matches, and to come back every time is quite an effort," said Federer.
"I am a little bit disappointed that I couldn't pick up my rhythm quicker, after I've won here twice."
The Swiss made a number of unforced errors early on and looked to have no feel for the ball with his returns particularly poor.
Ferrero, a former world number one but now ranked 98 after his 2004 season was ravaged by sickness and injury, took advantage to claim the first set with reasonable ease.
WILD FOREHAND
The Spaniard broke to lead the second set 1-0 when Federer made a wild forehand error but the top seed then lifted his game to finally look like the world's best player.
Federer levelled at 2-2 when Ferrero netted an overhead while off balance, before dominating the remainder of the set.
The final set was more equal with Ferrero gaining the first advantage, breaking to lead 4-2, but he struck his third double-fault of the match to lose serve in the next game.
The set then moved on to a tiebreak and after Ferrero made errors to lose his two match points, an aggressive forehand left Federer serving for victory. He closed out the match with a service winner.
"I haven't been playing well, but I've been coming through," Federer added. "I'm winning the crucial points and that shows I'm on top of my game when I have to be."
In other games, third seed Tim Henman struggled against Russia's Igor Andreev early on but after edging the first set in a tiebreak the Briton was able to dominate the second, breaking for 2-0 and 5-1 on the way to claiming a 7-6, 6-1 victory.
Seventh seeded Russian Mikhail Youzhny beat Germany's Rainer Schuettler 7-5, 6-4 but eighth seed Ivan Ljubicic of Croatia had a much tougher task in disposing of Spain's Fernando Verdasco 6-7, 6-4, 7-6.