Top-ranked Andre Agassi became the first player to advance to the semifinals of the ATP Tour World Championship by beating Gustavo Kuerten, 6-4, 7-5, today.

Agassi advanced to the last four without dropping a set in his three Red Group matches.

Kuerten, a Brazilian ranked No. 3 in the world, had 13 aces, and was the first player to break Agassi's serve in the tournament. But in the end, the American had too much precision and power for the former French Open champion.

The Red Group will be decided Friday, when Pete Sampras plays Nicolas Lapentti. Kuerten, 1-2, theoretically still could advance. Sampras is 1-1 and Lapentti is 0-2. Sampras needs to win a set to advance.

In the White Group, Nicolas Kiefer beat Todd Martin, 6-3, 6-2, to stay alive and Yevgeny Kafelnikov picked up his second victory by outlasting Thomas Enqvist.

Kafelnikov, No. 2 in the world, raised his record to 2-0 after beating Enqvist, 7-5, 3-6, 6-4, while the fourth-ranked Enqvist dropped to 1-1.

Because of the round-robin format, all four were still in the running for the two semifinal places. Kiefer is 1-1 and Martin fell to 0-2. The group will be decided Friday.

The $3.6 million season-ending tournament brings together the top eight players in the world, who are split into two groups. The top two from each pool advance to the last four.

After his victory, Agassi received the ATP Tour trophy for finishing the year as No. 1. Agassi will stay No. 1 for the year even if he fails to win the event.

"It symbolized a lot for me professionally and personally," Agassi said after receiving the glass trophy. "It's a big accomplishment for me."

Agassi seized the No. 1 ranking after winning the French Open and the U.S. Open.

Kafelnikov broke Enqvist's serve for a 2-0 lead in the final set, only to drop his own serve in the seventh game.

But Enqvist was unable to use his opportunity, and saved two match points on his serve in the 10th game.

Kafelnikov, who overcame 18 aces by Enqvist, set up his third match point with a passing shot. Then Enqvist's backhand sailed into the net.

The outcome was a repeat of the Australian Open final, when Kafelnikov also won.

Enqvist has risen to a career-high No. 4 in the world after winning the Eurocard Open in Stuttgart, Germany, and the Stockholm Open in his homeland in the run-up to Hanover.