The Associated Press

KEY BISCAYNE, Fla. - Hot weather, a formidable foe, rowdy fans and the law of averages failed to faze Serena Williams.

Still unbeaten in 2003, the top-seeded Williams rallied past Jennifer Capriati for the seventh consecutive time Saturday, 4-6, 6-4, 6-1, to win the Nasdaq-100 Open.

Playing on her 27th birthday didn't help Capriati, the runner-up for the third year in a row. She also lost to Serena last year and to Venus Williams in 2001.

Andre Agassi, bidding for his sixth Key Biscayne title and his third straight, will play No. 5 Carlos Moya in the men's final Sunday. Agassi, seeded second, advanced by beating No. 9 Albert Costa 6-2, 6-4.

The No. 6-seeded Capriati started fast but acknowledged that the 85-degree heat - and Williams' relentless groundstrokes - took a toll in their two-hour slugfest. By the final game, Capriati was hitting so wildly that Williams had to duck out of the way of one shot.

"It was pretty hot out there," Capriati said. "It's tough chasing down her balls."

Said Williams: "I saw she was getting tired. And I was just starting."

Both players consider Key Biscayne their home tournament. But while Williams wore Florida orange, the noisy stadium crowd was firmly in Capriati's corner - and disruptive during at least a couple of points.

"If anything, it motivates me to want to win," Williams said. "I can understand - it's her third time in the final. Honestly, if she was playing anyone else, I would have liked to see her win."

Williams can afford no room for sentiment because she has set a goal of going undefeated in 2003, which would be an unprecedented achievement. So far she's 17-0.

"It's going to be really hard," she said. "That's what I'm going to try to do, but I don't know if it's possible."

Beating Capriati seven consecutive times would hardly seem possible, and each match during the streak has been close. Even after Williams dropped a set for the first time in the tournament, Capriati found herself at a psychological disadvantage.

"I came out playing great," Capriati said. "For some reason, instead of keeping up that kind of level, I just back away. I don't know if it's a matter of me not believing that I can do it consistently for whatever it takes."

There are other factors in Williams' domination of the rivalry: She moves faster, serves better and hits harder. An exchange in the second game was telling. Capriati cracked a solid 95-mph serve, and Williams sent it back even faster for winner.

That was one of Williams' few crisp shots in the early going, but her high-wire game steadied in the second set, and she won nine consecutive points early in the third to grab the lead. Taking a big swing on almost every stroke, Williams finished with 42 unforced errors to 21 for Capriati, but compensated with a big advantage in winners - 33 to 13.

"She goes for it," Capriati said.

A more mellow Capriati has been the talk of the tournament, and her new laid-back attitude was tested by several disputed calls and fan interruptions.

One ruling sent Capriati to her knees in disbelief, but she complained only briefly. And when a spectator screamed "Get mad, Jennifer" as Williams closed in on the victory, Capriati could only smile.

"I thought it was kind of funny," she said.

A short time later, Capriati pulled a backhand wide on match point. Williams raised her arms and hopped up and down with glee, then accepted a check for $393,000.

Capriati again settled for runner-up money - $206,000. She has never won a Key Biscayne titles in 12 attempts, but just because she turned 27 doesn't mean she'll quit trying.

"I try not to think about the age and how old I am," she said. "I still feel like sometimes I'm 14 anyway."

The Agassi-Costa match looked like a marathon at the outset, with a first game that lasted 17 minutes and 26 points. Agassi won it to break serve, then went on to a 3-0 lead and was in control the rest of the way.

He finished with 29 winners and just 18 unforced errors to reach the final for the eighth time. With one more title Agassi would surpass his wife, Steffi Graf, who won five times at Key Biscayne.

"It would be nice, because then I can have Steff bring all her trophies home from this tournament," he said with a smile. "As of right now, she's not allowed to have all of them there."