SHANGHAI, China -- Lleyton Hewitt, Andre Agassi and Marat Safin -- the world's three top-ranked players -- were upset Wednesday at the Masters Cup.

	Carlos Moya, left, is pumped after beating Lleyton Hewitt on Wednesday.

Carlos Moya sprung the big surprise, beating Hewitt 6-4, 7-5 to become the first semifinalist of this elite, eight-player event. Had Hewitt won he would have all but clinched his second straight year-end No. 1 ranking.

Hewitt lost after Jiri Novak defeated Agassi 7-5, 6-1 and Albert Costa downed Safin 3-6, 6-4, 6-3.

"I thought I played a lot better tonight than I did last night," said Hewitt, who beat Costa on Tuesday. "He's playing unbelievable tennis right now. It's definitely not a bad loss losing to Carlos Moya."

Moya broke Hewitt for the final time in the 11th game. On his first match point, Hewitt hit a lob that was going wide. But Moya, standing outside the sideline, smashed a cross-court shot wide. He needed two more match points before winning.

"It was just the big points that got away from me tonight," Hewitt said.

He is trying to become the first player since Pete Sampras in 1996 and 1997 to win the event two consecutive years.

The top two players in each four-man group advance from round-robin play to Saturday's semifinals of the $3.75 million tournament.

Agassi's game deserted him late in the first set. He dropped the second set to his Czech opponent in 21 minutes.

"He raised his level late in the first set and I had no answer for it," Agassi said.

Early on, it appeared Agassi would have an easy night as he pasted the lines with groundstrokes and occasionally sneaked to the net for volleys.

But after he served a love game to move up 5-2, he changed his shirt -- and that's when the match changed as well. Novak, who is coming off a groin injury, ripped through the next five games, breaking Agassi in the ninth and 11th games.

"He stepped up the baseline rallies," Agassi said. "He was starting to take some chances and played more aggressively. ... I was pretty much outplayed in every department from that point on."

Agassi struggled to hold serve to begin the second set after being taken to deuce. He didn't win another game.

Novak finished with 22 winners, three more than Agassi, but had only 10 unforced errors to 23 by his opponent.

"You have to find a way mentally to hang in there and give yourself a chance," Agassi said. "And today I lost a little concentration. The whole match turned and I never made an adjustment. So I really wasn't deserving of a victory today."

Costa evened his record at 1-1. Safin dropped to 0-2, with Hewitt his next opponent.

On the final point of the second set, Safin hit an ill-advised drop shot that Costa easily put away. The Spaniard raced ahead 4-1 in the final set, closing it when Safin's forehand sailed wide.

"Sometimes matches can be decided in just a couple of points, and I fought and fought," said Costa, a clay-court specialist. "Fighting is easy for me. Maybe I am fresher than the other guys here. Not so confident, but more fresh because I have played fewer matches. I had a back injury and did not get wins indoors this season."

"I should have won today. I lost my game completely and I couldn't get it back," Safin said. "Even with 16 aces, it was not good enough. You cannot have every day perfect in your life. It's like a normal person has bad days, good days. This week I had two bad days in a row."

Information from SportsTicker was used in this report.