Novak Djokovic advanced to the semi-finals of the ATP Tour Finals with a 100 per cent record as the world number one defeated Czech fifth seed Tomas Berdych 6-2, 7-6 (8/6) at London’s O2 Arena yesterday.

Djokovic had already defeated Andy Murray and Jo-Wilfried Tsonga in his previous Group A matches and the Serb knew he needed only to win one set against Berdych to be sure of qualifying.

The 25-year-old achieved that goal in just over half an hour, but he refused to take it easy after that and secured the victory which guaranteed first place in the group and potentially an easier route to the final.

In the process, Djokovic also secured his 73rd match win of 2012, moving him level with David Ferrer as the year’s two most successful players on the Tour.

Berdych’s second loss of the tournament means he is eliminated, while US Open champion Murray sealed his place in the last four of the tournament after beating Tsonga 6-2, 7-6 in the night match.

Djokovic had won 10 of his previous 11 encounters with Berdych and the Serb was quick to take command, breaking for a 2-1 lead when Berdych netted on the fourth break-point of the game.

Djokovic was dictating the tempo of the rallies and the unnerved Berdych, unable to cause much damage with his booming serve, surrendered a second break in the fifth game that effectively ended the first set.

With his last four place now secured, Djokovic looked like sprinting to victory when he broke to go 2-1 ahead in the second set, but a loose service game presented Berdych with an unexpected lifeline.

That gave renewed impetus to Berdych and the set went to a tie-break.

The Czech looked certain to force a final set when he raced into a 6-3 lead in the breaker.

But Djokovic once again showed tremendous resolve as he saved all three set points and then shattered with Berdych with a mini-break of his own to seal the win.

Novak Djokovic