Novak Djokovic of Serbia hits a return to compatriot Janko Tipsarevic during their singles tennis match at the ATP World Tour Finals in the O2 Arena in London, Nov 25, 2011. [Photo/Agencies]

LONDON - World number one Novak Djokovic followed Rafa Nadal and Andy Murray out of the ATP World Tour Finals on Friday when he lost to fellow Serb Janko Tipsarevic for the first time.

As round-robin action concluded at the O2 Arena a jaded-looking Djokovic was beaten 3-6 6-3 6-3 to end Group A with two defeats and one victory and leave Roger Federer as the only member of the 'Big Four' to reach the weekend.

Djokovic would still have squeezed into the semi-finals of the season-ender through the back door had David Ferrer beaten Tomas Berdych later on Friday but the Spanish dynamo also appeared to run out of steam, going down 3-6 7-5 6-1.

After staring elimination in the face when he twice went a break down in the second set, Berdych roared back to win Group A and thus avoid a semi-final against holder Roger Federer who is red-hot favourite for a record sixth title at the tournament.

The Czech instead faces Jo-Wilfried Tsonga, the charismatic Frenchman who sent Nadal packing on Thursday, in one semi-final while Ferrer's punishment for letting Berdych off the hook is a clash with Federer who he trails 11-0 in career meetings.

"I never win against Roger and I hope I can change that," Ferrer, who led 4-3, 40-15 in the second set against Berdych, told reporters before walking away rather stiffly to try and recover for Saturday's first semi-final.

Janko Tipsarevic of Serbia hits a return to compatriot Novak Djokovic during their singles tennis match at the ATP World Tour Finals in the O2 Arena in London, Nov 25, 2011. [Photo/Agencies]

Trio out

Djokovic's exit means the top three players in the world all failed to survive the group stage although in Murray's case he withdrew after his loss to Ferrer with a groin injury.

Tipsarevic, who replaced Murray, walked off with earnings of $190,000 after finishing his year with a first ever victory over close friend Djokovic - $70,000 as his fee for being the on-site alternate and $120,000 for his sole win.

While he was delighted with his victory, Tipsarevic admitted his opponent, winner of three of the year's four grand slam titles, was not firing on all cylinders.

"I'm not trying to undermine my performance or my victory today, but I can freely say that this was not Novak Djokovic from the US Open or Wimbledon," he said.

Djokovic, who will holiday with Davis Cup team mate Tipsarevic in The Maldives next week, admitted the tournament had been a bridge too far.

"My body says that it's overload," Djokovic, who ended the year with a 70-6 record after his first back-to-back defeats since March 2010, told reporters. "It has been too much this year. Obviously, mentally I feel a little bit drained."

Novak Djokovic of Serbia reacts after losing a point to fellow compatriot Janko Tipsarevic during their singles tennis match at the ATP World Tour Finals in the O2 Arena in London, Nov 25, 2011. [Photo/Agencies]