Nadal, ranked No. 2 in the world behind Federer, had been unbeaten on the surface since April 2005, a run that included 13 titles.

"If I have to lose against anyone, then he is the man," Nadal said.

Federer's come-from-behind win was his first over Nadal on clay in six matches. Nadal leads the overall series 7-4.

The win ended Federer's drought after he failed to win a title in his last four events, his worst run since he became world No. 1 in February 2004.

"Eighty-one matches is an amazing series," Federer said. "I have a lot of respect for him."

Federer has won in Hamburg in four of his last five visits.

"It's great to play here again and win again," he said. "I've fallen in love with this tournament."

The Swiss has three titles this year, having already won the Australian Open and in Dubai.

The victory over the man who has dominated him on clay before will boost Federer's' confidence one week ahead of the French Open, the second major of the year and the only Grand Slam Federer has not won. Nadal has won the French Open for the last two years.

"I congratulate Roger and wish him good luck at the French Open," Nadal said.

At the start of the match, it looked like Nadal would extend his streak easily.

He raced through the first set, with Federer making many errors and having trouble with his serve.

But the match turned completely when Federer broke serve for a 2-1 lead in the second.

The Swiss played patiently, stopped making errors and his serve returned.

Nadal, on the other hand, began to struggle with his shots and even his fierce forehand frequently began to go long or wide.

Federer took advantage and won a set at love against Nadal for the second time since beating him in the final at Wimbledon last year.

The Swiss won 76 percent of his first-serve points, compared to Nadal's 52 percent. Federer also had more winners, 31 to 20.

Federer earned $458,218 for his win, and Nadal half of that.

ATP clay court win streaks

81 — Rafael Nadal, Apr. 2005-May, 2007

53 — Guillermo Vilas, May-Oct. 1977

46 — Bjorn Borg, Oct. 1977-May 1979

40 — Thomas Muster, Feb.-June 1995

38 — Thomas Muster, Aug. 1995-Apr. 1996