HALLE, Germany — Roger Federer won his 10th title on grass Sunday to match Pete Sampras' total, beating Philipp Kohlschreiber 6-3, 6-4 in the Gerry Weber Open final.

Federer, who sailed through the Wimbledon warmup tournament without losing his serve, ran his record unbeaten run on grass to 59 matches.

Kohlschreiber hit a backhand into the net after a long rally to end the match in 73 minutes, giving Federer his 55th career title.

"I'm really excited; I think that's the first time in my career I won a title" without losing serve, Federer said. "That was very special — and I'm very proud to keep my streak going."

In fact, Federer also won a tournament in Doha in 2005 without being broken.

The top-ranked Swiss restored some confidence after one of his worst defeats — a rout in the French Open final last Sunday at the hands of rival Rafael Nadal. Federer took just four games.

"I didn't want to lose in the first and second round," Federer said. "I felt the pressure early on, but I felt great as the week wore on. I felt like I had a spring in my step — that's important after the start of the year."

He was diagnosed with mononucleosis earlier this year, and has won just two titles in 2008.

Federer, who raised his record to 10-0 in grass finals, won Halle for the fifth time. The previous four were followed by Wimbledon triumphs three weeks later.

"That's exactly what I hope for this time," Federer said. "That's why I'm so satisfied. That's why I will go to Wimbledon with a lot of hope."

But he will face an even tougher challenge from Rafael Nadal this year. The Spaniard, who lost the last two Wimbledon finals, won his first grass-court title Sunday with a win over Novak Djokovic at Queen's Club in London.

Federer didn't face a top 10 player in Halle, but was stronger than his last appearance at the event in 2006. He was pushed to three sets in four of his five matches that year.

He started slow in front of 12,000 spectators as rain forced the roof on center court to be closed midway through the match.

Kohlschreiber, looking for his second title this year after Auckland, had two break chances at 1-1 in the first set. Federer saved with an ace and a passing shot.

"I was, maybe, a hair better than Roger at the start," Kohlschreiber said. "But that's why he is No. 1. He adjusts to your game and I hardly had chances later."

Federer won Halle for the first time in 2003 — before going on to win his first Wimbledon title — and now has won 25 straight matches at the tournament.