NEW YORK, NOV. 18 -- A new generation of players has been knocking at the door in women's tennis all year. Today those players came in -- with a vengeance.

Leading the way was 16-year-old Monica Seles who, in an enthralling five-set final of the $3 million Virginia Slims Championships at Madison Square Garden, outlasted 20-year-old Gabriela Sabatini, 6-4, 5-7, 3-6, 6-4, 6-2. This was high-voltage tennis with the women playing at physical levels they may never have reached before. The fans responded with the same kind of energy. For 3 hours 47 minutes, the crowd of 17,290 was electrified as Sabatini and Seles showed the best their sport has to offer: sheer power, unflagging determination and ballet-like finesse on the court. It was the first time in 89 years that women had played a five-set match. The Virginia Slims championships instituted the best-of-five set final in 1984, but no match had gone more than four sets until today. The last five-setter for women came in the U.S. Nationals in Philadelphia in 1901.

"It was an unbelievable match," Seles said. "We both played great. Women's tennis is at its best right now."

Seles' semifinal victory on Saturday already assured her the No. 2 ranking. Today's win marked her second major win of the year -- she took the French Open -- and it entrenched her in the top echelon of the women's game.

The Yugoslav also became the youngest player to win the Slims year-end championships, and took home $250,000 for her efforts.

As the match wore on, fatigue set in but there was no deviation from the caliber and style of play. It was a slugfest from the baseline, punctuated by Sabatini's elegant, delicate drop shots and explosive overheads.

Third-seeded Sabatini, who upset favored and top-ranked Steffi Graf in the semifinals, started slowly today, and throughout the first set the powerful Seles looked in control. Sabatini was tentative, missing too many first serves and having difficulty advancing to the net because of the persistent depth and angles of Seles' ground strokes.

Seles, meanwhile, calmly did what she does best: hit the ball hard.

In contrast to Sabatini, who uses classic, looping topspin ground strokes, Seles drills the ball on almost every shot. She ruthlessly aims for the corners and is content to clear the net by the smallest possible margin. Today was no exception. For the first 15 games she used her two-fisted ground strokes to hit winner after winner, the balls greasing the lines.

Sabatini struggled to keep up. Serving at 3-5 in the first set, she needed seven advantage points before winning the game.

With the crowd continuing its support for her, the Argentine finally came alive in the sixth game of the second set. Taking a page from Seles' book, Sabatini began hitting with abandon off both sides and for the first time in the match began to take control of the net.

"She didn't give me many chances," Sabatini said. "I decided to start attacking. It was the only way I could beat her."

Sabatini relied on two big overheads to break Seles before winning the second set, 7-5. In the third set, she continued to play with authority, finding particular success with a potent backhand. Both players held serve until Sabatini broke Seles in the eighth game to lead 5-3, then polished off the set with an ace.

Neither player appeared to wither from the pressure. In the fourth set, Sabatini staved off two set points with blistering backhand winners before double-faulting on set point in the 10th game.

The drama finally ended when Seles hit a crosscourt backhand that sent Sabatini lunging futilely toward the sideline.

The tournament this week, which featured the top 16 women players in the world, was a showcase for the new, youthful energy that has infused women's tennis. Instead of the domination by Graf and 34-year-old Martina Navratilova, five or six players now seem capable of winning the big tournaments.

Although Sabatini lost today, she has made giant strides in her game. Having slipped to No. 5 in the middle of the year, she hired a new coach, worked with a sports psychologist and developed a new arsenal of shots.

The results were striking. After several years in which Sabatini seemed to accept Graf's superiority, she had an awakening over the summer and began to play with confidence, defeating Graf in the final of the U.S. Open for her first Grand Slam title.

While Seles' performance this week signals a new era for her, she will have to show more consistency if she is to wrest the top ranking away from Graf. Graf, despite a disappointing year in which she won only one major tournament -- the Australian Open in January -- compiled by far the best record in the game (72-5) with all losses either in the finals or semifinals and 10 victories.