SHANGHAI, China -- Lleyton Hewitt has the No. 1 ranking. He also has a semifinal berth at the season-ending Masters Cup, thanks to Carlos Moya.

Hewitt, the defending champion in the eight-man tournament, advanced to the semis when Moya outlasted French Open champion Albert Costa 7-6 (7), 3-6, 6-4 Friday night. If Costa had won, Hewitt's season would have been over.

"It wasn't easy to handle that situation, knowing that if he was winning the match, he was going to qualify, and if he was losing, he wasn't,'' Moya said. "So I tried to be honest with myself and honest with the sport and honest with tennis.''

The last semifinal spot went to Juan Carlos Ferrero, who defeated Jiri Novak 7-5, 6-3. The round-robin portion of the tournament ended when Switzerland's Roger Federer beat Thomas Johansson 6-3, 7-5. Johansson was an alternate for Andre Agassi, who withdrew from the tournament Thursday with a hip injury.

Hewitt, who clinched the year-end No. 1 ranking Thursday when Agassi lost to Ferrero, will take on Federer on Saturday. The other semifinal pits Moya against Ferrero.

Moya squashed all speculation that he might not play his best so that Costa, a fellow Spaniard, could win and reach the semifinals. Instead, Moya's best was just good enough to run his record to 3-0 on the indoor purple court.

What began as a sloppy affair turned into a well-played contest -- until the last game. Costa apparently was injured and committed three unforced errors before trying an ill-advised drop shot that Moya turned into a game-winning volley.

Costa said he "felt like I had been punched'' while he was walking between points during the last game.

"I was just about to play and I was feeling blocked,'' Costa said. "I was feeling bad and I couldn't play my game. That's what happened. Not during the point, when I was walking.''

Costa finished with a 1-2 record. Hewitt was 2-1 and Marat Safin lost all three of his group matches.

Ferrero controlled the points from the baseline and was too strong for Novak. After winning the opening set, Ferrero took a 4-1 lead in the second and held serve to close out the victory.