NEW YORK (AP) -- Serena Williams did her part by dethroning Lindsay Davenport as U.S. Open champion Friday, but big sister Venus limped off in defeat to Martina Hingis and missed a chance at a historic all-in-the-family final.

Serena reached her first major final with the aid of a shanked shot that squirted in for a key break and 12 aces that helped seal the victory. The muscular, 17-year-old came back from a dreadful drubbing in the second set, in which she lost 14 of the last 16 points, then put on a buoyant display of grit and athleticism to win 6-4, 1-6, 6-4.

Venus, who was 17 when she lost in the final against Hingis two years ago, couldn't complete the sister-sister matchup that their father, Richard, had been predicting the past few weeks.

``Now she's playing for two people,'' Venus said. ``Hopefully, I gave Martina a good workout today.''

In an exhausting duel that left Williams cramping at the end and barely able to reach the net on serves, Hingis came through with a 6-1, 4-6, 6-3 victory.

``It was a tremendous match, especially in the third set,'' Hingis said. ``I tried to keep her running. I knew she was cramping.

``I just didn't want that finals to happen, Williams-Williams.''

Hingis said she'd heard more than enough of Richard Williams' predictions.

``They're three against me, so talking I can't beat them,'' she said. ``I have to beat them on court.''

It was more a battle of wills than a display of beautiful tennis with Venus' serve broken nine times and Hingis' six. But what it lacked in aesthetic value, it certainly more than made up for in tension and effort with both players producing spectacular shots at times.

None was better than the one Hingis produced to set up match point. Williams had flicked a deft drop volley near the sideline, across the court from Hingis, but the 18-year-old from Switzerland chased it down and sent a running one-handed backhand over the net post into the corner.

The crowd roared at that shot, as it had on so many others, and Hingis followed it up with a service winner to advance to her third Grand Slam final this year and seventh overall.

``I lost a lot of speed on my serve in the middle set,'' Williams said. ``I definitely didn't feel good at that point. We were both doing a lot of running. I was moving her and she was moving me. I'm sure she was tired. She was breathing hard, struggling to get shots.''

Rain delayed the start of the semis by 2 1/2 hours, and the players had to cope with conditions that ranged from glaring sun to dark gray shade.

Little separated Serena Williams and Davenport in the first set until the last game, when Williams came up with a darting volley crosscourt for deuce. Davenport netted a forehand on the next point, then couldn't handle a deep forehand by Williams on set-point.

Venus watched the first set at courtside, then retreated to warm up for her match.

Davenport, No. 2, seemed on the way back to the final when she raced through the second set in just 24 minutes and allowed Williams only two points in the three service games she was broken.

``Lindsay was playing just unbelievable,'' Williams said. ``She was hitting shots for winners, just attacking everything. I became really determined. I was, like, 'I'm tired of this. I want something also.'''

Williams, seeded No. 7 and playing in only her second U.S. Open, found the range again when she served for the first time in the third set. She unleashed three straight aces to let Davenport know she wasn't going away.

They stayed on serve to 3-3, when Williams gained the first break-point of the set with a running forehand volley crosscourt after a superb rally.

Then luck entered the equation.

Williams lunged to her right to reach for a return and squirted a mis-hit shot just over the net. A surprised Davenport ran in to scoop it up awkwardly, but slapped it long to fall behind 4-3.

``After 17 years, I say I deserve a break once in a while,'' Williams said with a smile.

She made her own luck after that, holding serve to 5-3 after fending off five break-points in an eight-deuce game.

Davenport's strategy through the match was to take aim at Williams' backhand, the most vulnerable part of her game. That tactic paid off in the second set, but wasn't enough to take the match.

``I felt that if I won that game, I would have a great chance of winning the match because all I had to do was hold serve,'' Williams said. ``I felt if Lindsay won the game, I would have to fight. I was never going to give up. I never at one time felt I was going to lose.''

Williams' relentlessness and sheer power on serve proved the difference in the end, as she closed out the last game with three service winners and an ace that ran her tournament total to 54, the most of any woman.

``I really think I've developed mentally a lot,'' Williams said. ``I'm more composed out there. I didn't get nervous or anything. I just stayed determined and focused. I'm able to pull through.''

Davenport, one of the game's best returners, looked helpless at times when Williams served.

``Every break-point I had, she just hit a huge, huge first serve,'' said Davenport, who won her second Grand Slam title at Wimbledon two months ago.

``She has a great serve, one of the best in women's tennis, if not the best. She throws in one at 115 mph, then she'll slow it up. She has a great kick serve. She mixes it up better than her sister does. That's what you have to deal with -- the serve, getting them back, but still be aggressive. It's a hard thing to do.''

In making her surge up the rankings in her second year on the tour, Williams won three WTA Tour titles, the most recent at Manhattan Beach, Calif., last month when she beat Hingis in the semifinals.

Serena and Venus became the first sisters to meet in a WTA Tour final when they played on a hardcourt at the Lipton in Key Biscayne, Fla., in March. Venus took that title, 6-1, 4-6, 6-4, to run her record to 3-0 against Serena.

In their previous pro matches, Venus won on a hardcourt in the second round of the 1998 Australian Open, and on clay in the quarters of the 1998 Italian Open.