Paris - Roger Federer dug himself out of danger from two sets to love down, overhauling Tommy Haas 6-7 (4-7), 5-7, 6-4, 6-0, 6-2 Monday to save himself the fate that befell Rafael Nadal a day earlier at the French Open. The fighting second seed emerged a winner after more than three hours as he succeeded in escaping the ultimate danger for the second time in as many Grand Slams. It marked the fifth time in his career that Federer managed the feat.
He also had to struggle out of another two sets to love down at January's Australian Open to get past Tomas Berdych in the fourth round.
The Swiss, his path somewhat cleared by the weekend shock elimination of four-time champion Nadal by free-swinging Swede Robin Soderling, still had to battle past Haas for his eighth consecutive win over the German who last beat him in 2002.
"It was a great battle for me, and I'm thrilled to be through and given another chance here," said 13-time Grand Slam champion Federer.
Federer fired 16 aces and 60 winners, breaking seven times. It was his second recovery from the depths in Paris, having beaten Sargis Sargsian at Roland Garros in 2001 from two sets to love down.
He next faces Frenchman Gael Monfils, who humiliated Andy Roddick in fading light 6-4, 6-2, 6-3.
Argentine fifth seed Juan Del Potro continued his powerful march through the fortnight, crushing French hopes with his defeat of Jo- Wilfried Tsonga 6-1, 6-7 (5-7), 6-1, 6-4. Del Potro will next play Spain's 16th seed Tommy Robredo, a winner over German Philipp Kohlschreiber 6-4, 5-7, 7-6 (7-4), 6-2.
"I thought actually I was serving all right, especially for a set and a half," said Federer. "I was down a set but up in the second set, unfortunately I got broken.
"That definitely made me a little bit nervous, just knowing that I still hadn't really found my range and my rhythm from the baseline.
"Tommy was also serving himself extremely well, mixing up his game very well. So I definitely felt under pressure there."
It was the second Grand Slam from the last three where Haas let a two-sets-to-love lead slip away. He was beaten in the US Open second round last year by Gilles Muller from a similar winning position and has now failed to fire while holding the lead on six occasions.
"When you are that close to winning, it hurts, obviously," said the German. "When you play against the second best player in the world on center court and you know you have a chance to maybe close it out and maybe serve it out for the match...," he said of the third set, where the contest turned.
"But this is tennis, it's sport. It's never over till the last point, and we all know that when we go out there. It's just what happens."
In women's play, second seed Serena Williams crushed nervous Canadian Aleksandra Wozniak 6-1, 6-2 while Russian Svetlana Kuznetsova beat Poland's Agnieszka Radwanska 6-4, 1-6, 6-1,with the winners set to meet in the last eight.
"I'm getting better every day," said Williams, "I'm just happy to still be here in my preparation, still just getting there."
The American took full advantage of her 21-year-old opponent's inexperience on the big stage.
"After I got off to such a quick start, I realized that maybe she hadn't played on centre court yet. Maybe she hadn't had the experience in big matches in Grand Slams where there is a chance for either player who won to get into the quarter-finals."
Samantha Stosur became the first Australian into the Paris quarter-finals since 1988 with her defeat of Virginie Razzano 6-1, 6- 2, Romanian teenaged Sorana Cristea knocked out her second top ten player in an upset of fifth seed Jelena Jankovic 3-6, 6-0, 9-7.