MADRID — The way Rafael Nadal has been playing on clay, it's hard to imagine he won't take home a fifth French Open title this year.

Nadal improved to 15-0 on clay this season and won a record 18th Masters title yesterday, beating top-ranked Roger Federer, 6-4, 7-6 (5), in the Madrid final.

Nadal, who will return to No. 2 in today's rankings, dodged questions about being the favorite at the French Open starting May 23.

"I'm very happy with everything so far this year. I think I've returned to my top form and that's the most important thing for me," Nadal said. "Am I favorite to win at Roland Garros? I was last year and I lost."

Nadal, hampered by nagging knee injuries last season, reversed the result of the 2009 final — the last time he and Federer faced each other — to win in Madrid for a second time and move one Masters title ahead of Andre Agassi and two in front of Federer.

"The most important thing is winning at home; winning in Madrid is a dream. After that, I think about the ranking," said Nadal. "Against this opponent, it's always going to be difficult."

In the women's final, Venus Williams was beaten 6-2, 7-5 by unseeded Aravane Rezai of France.

Nadal also won titles in Monte Carlo and Rome to become the first player to win all three titles in the same season. The Spaniard has lost only two sets during that run and is 14-7 all-time against Federer, including 10-2 on clay.

"I wasn't able to defend my title here today but I thought Rafa played an incredible clay-court season," said Federer. "I'm looking forward to Paris now. I'm happy with my clay-court game."

Both players dropped serve early in the first set before the second-seeded Nadal broke decisively to lead 4-3 against the Swiss player.

In the second set, Nadal claimed a tightly contested tiebreaker after two breaks of serve each.

Rezai rallied from two breaks down in the second set to win her third career title.

Rezai was making her second appearance at the Madrid Masters and came in having lost in the first round in Barcelona and the second in Rome. She ended up dropping only one set throughout the tournament.

AUSTRALIA, U.S. TIED IN WORLD TEAM CUP

Lleyton Hewitt beat John Isner in straight sets yesterday to pull Australia into a tie with the United States on the opening day at the World Team Cup in Duesseldorf, Germany.

Sam Querrey put the Americans ahead by beating Peter Luczak, 6-7, 7-6, 6-3, but former No. 1 Hewitt outplayed 19th-ranked Isner in a 6-2, 6-4 victory to even the score.

A doubles match today will decide the winner of the opening tie in the Red Group, which also includes Spain and the Czech Republic.

The Blue Group is made up of Argentina, France, Germany and defending champion Serbia.

The winner of each group will meet in Saturday's final.

SEPPI BEATS BERRER IN OPEN DE NICE

Andreas Seppi of Italy beat seventh-seeded Michael Berrer of Germany, 6-3, 7-5, in the first round of the Open de Nice yesterday in Nice, France.

Seppi broke Berrer four times at the Nice Lawn Tennis Club. He will next face Sergiy Stakhovsky of Ukraine, who rallied to defeat Jarkko Nieminen of Finland, 2-6, 6-3, 6-4.