Djokovic suffers second loss at ATP Finals

Novak Djokovic of Serbia reacts during the match against Janko Tipsarevic of Serbia at 2011's ATP World Tour Finals in London, Britain, Nov. 25, 2011. Tipsarevic won 2-1. (Xinhua/Zeng Yi)

Janko Tipsarevic of Serbia returns a shot during the match against Novak Djokovic of Serbia at 2011's ATP World Tour Finals in London, Britain, Nov. 25, 2011. Tipsarevic won 2-1. (Xinhua/Zeng Yi)

Novak Djokovic of Serbia leaves the court after the match against Janko Tipsarevic of Serbia at 2011's ATP World Tour Finals in London, Britain, Nov. 25, 2011. Tipsarevic won 2-1. (Xinhua/Zeng Yi)

LONDON, Nov. 25 (Xinhua) -- World No. 1 Novak Djokovic suffered his second defeat at the ATP World Tour Finals as he lost to Janko Tipsarevic on Friday.

Djokovic, 24, took the first set 6-3, but lost the following two 3-6 and 3-6 to his countryman Tipsarevic.

"I lost the match that I think I was on the way to win. First set I played well," said Djokovic. "But if this is my last match in the finals, I'll be happy because I think at least comparing to the match against Ferrer, I played a little bit better."

Two days ago, Djokovic was defeated by Spain's David Ferrer, who then earned a semifinal berth with two straight wins.

But the Serbian could still reach the semifinals as long as David Ferrer beats Tomas Berdych later in the last group A match this evening.

"I will do more or less everything like I'm playing. If I have a chance, and I have a decent chance it can happen," said Djokovic. "I think David is playing well, so it can happen that he wins against Tomas, then I would play against Roger tomorrow. So I will prepare."

Roger Federer reached the semifinals as the first in Group B as the Swiss master won all three group matches.

Frenchman Jo-Wilfried Tsonga was the second in this group as he ousted world No. 2 Rafael Nadal from the season finale to reach the semifinals for the first time on Thursday.