Roger Federer [Images] reached the semi-finals of the Masters Cup on Wednesday without hitting a ball, then beat Ivan Ljubicic 7-6, 6-4 to bring defending champion David Nalbandian through with him.

Argentine Nalbandian improved to 1-2 for the round robin stage by downing Andy Roddick [Images] 6-2, 7-6 earlier in the day, sending Swiss Federer through and ending his American opponent's interest in the tournament.

Nalbandian was left needing world number one Federer to beat Ljubicic in the second match of the evening to stay in the championship and despite being broken in his first service game, Federer duly delivered.

Federer crushed the Croatian to become the first player to win 90 matches in a season since Ivan Lendl won 106 in 1982, extended his winning streak to 27 matches and ensured he will remain unbeaten in Masters Cup round robin matches for at least another year.

Champion in 2003 and 2004 and beaten finalist last year, Federer qualified for the semis for the fifth year in a row after winning all three of his Red Group matches.

American James Blake qualified for the last four from Gold Group on Wednesday evening, while world numbers two and three, Rafael Nadal [Images] of Spain and Russian Nikolay Davydenko, face off for the final slot in the semis on Friday.

Fifth ranked Roddick, a shadow of the player who came close to upsetting Federer on Tuesday, joins Spain's Tommy Robredo in being eliminated from the tournament.

"Give credit where credit's due, I didn't play badly tonight, I hit the ball through the court ... but he played very well," said Roddick.

The 24-year-old American started poorly and Nalbandian pounced on his below-par serves to break in the first game of the match.

"In the beginning I played very good," said Nalbandian, who was playing despite learning of the death of his nine-year-old godson in an elevator accident back home in Cordoba.

"I was hitting good shots and got control of the match. He didn't serve so good, that's why I went away."

The second set was closer with Roddick getting his ace count up but his approaches to the net were still laboured -- he won just nine of 23 net points in the match -- and Nalbandian broke him again to lead 4-3.

Roddick broke back when his opponent was serving for the set but it only delayed his defeat as he gave up a 3-1 lead to lose 7-4 in the tiebreak with a series of errors to give Nalbandian his glimmer of hope.

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