Serbia's Novak Djokovic advanced to the semifinals of the ATP World Tour Finals with a 6-2, 7-6 (8-6) victory here Friday over Czech Tomas Berdych

Djokovic took control of his final Group A round-robin match at London's O2 Arena from the outset, counteracting the serving power of the Czech with deep returns and wearing his opponent down with long baseline rallies.

After winning the first set in routine fashion and going up a service break early in the second set, the match became more complicated for the world No. 1 in the latter stages.

Berdych got his lone service break in the fourth game of the second set, which Djokovic ended up ekeing out in a tiebreaker.

"It was quite close (second) set," Berdych, whose career record against Djokovic fell to 1-11, said. "I had some chances in the tie-break. It wasn't one of my best matches with him."

Berdych, who was eliminated from the tournament with the loss, could only look ahead to the Davis Cup final, which gets underway on Nov. 16.

"I hope that the best moment is still to come," Berdych, who will lead the Czech Republic against Spain, said.

Friday's night match will decide who finishes second in Group A and advances to the semifinals. Scotland's Andy Murray has the edge because he only needs to win one set to secure his berth in the final four.

In Group B, Swiss great Roger Federer has already secured his spot in the semifinals.

On Saturday, he will take on Argentina's Juan Martin del Potro in his last round-robin match, while Spain's David Ferrer will square off against Serbia's Janko Tipsarevic.

The eight-man World Tour Finals, the ATP's year-end championships, is the biggest tournament on the men's tennis calendar after the four Grand Slams. EFE