SHANGHAI, Nov.16 (Xinhua) -- World no. 1 Roger Federer of Switzerland scored a perfect 3-0 record in the round-robin Red Group to advance into the semi-finals here at the ATP Tennis Masters Cup by beating Croatian Ivan Ljubicic 7-6 (7-2), 6-4.

Before this match, Federer has already secured a berth in the semifinals as American Andy Roddick lost to Argentine David Nalbandian.

In the first set, Federer had a slow start and was broken in his first service game. But he got his form back quickly and broke Ljubicic's serve in the 6th game to earn himself a 3-3 tie.

Then Ljubici began to serve more strongly for he knew that if he lost, he would have no more match in Shanghai. But he could broke Federer again and the first set had to be decided by tiebreaker.

Federer gained an upper hand in the tiebreaker and won the set 7-2.

The second set went Federer's way and the world no. one won the match 6-4.

Ljubicic was quite puzzled with the qualifying result: "I beat Nalbandian and both of us only won one match. He qualified instead of me. That's curious."

Federer felt that he was feeling better than he was in the last two matches: "I'm pretty happy. I'm getting a bit better. My serve is reliable and we fought at the baseline."

"Nalbandian deserved to be in the semis. And I'm happy to meet him again in the final just like last year."