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.