Czech Republic's Tomas Berdych celebrates after defeating France's Jo-Wilfried Tsonga during their men's singles tennis match at the ATP World Tour Finals in the O2 Arena in London, Nov 7, 2012. [Photo/Agencies]

LONDON - Czech Tomas Berdych stayed in the hunt for a semifinal berth at the ATP World Tour finals with a 7-5 3-6 6-1 victory over Frenchman Jo-Wilfried Tsonga on Wednesday.

Berdych, who was beaten by Andy Murray in his opening Group A match on Monday, was the superior player for most of the contest although he did suffer a midmatch wobble.

Despite Tsonga raising his game to take the second set, Berdych powered through the decider to join Murray on one win in the group.

Novak Djokovic has two wins from two and last year's beaten finalist Tsonga is yet to get off the mark at the season-ender although all four players in the group can still make the semifinals, depending on final round-robin matches on Friday.

Victory for Tsonga would have guaranteed Djokovic a top-two finish in the group but the Serb will probably need to beat Berdych to make absolutely sure of progressing.

World number one Djokovic beat Murray in three sets in the day's early group match.