Novak Djokovic set up a semi-final clash with Roger Federer after defeating Andy Roddick in straight sets at the Barclays ATP World Finals.

Roddick went into the match still with a chance of qualifying for the semi-finals despite losses earlier in the week to Rafael Nadal and Tomas Berdych. The American needed to defeat Djokovic in straight sets, not an unrealistic prospect with Roddick having won their last four matches.

However Roddick looked deflated from the outset and had few answers to Djokovic's relentless hitting from the back of the court. The Serb came out with a clear game plan to target the Roddick backhand and did so relentlessly, enjoying much success with the kick serve out to that side.

Djokovic is the better mover of the two and possesses more firepower from the back of the court so to have a chance, Roddick needed to be willing to go after his forehand and take some chances in the forecourt but the American looked like he would rather be anywhere else than the O2 Arena. Djokovic outmanoeuvred him with ease and once he broke serve in the opening set the result was never in doubt.

Djokovic will play Federer on Saturday evening in the second semi-final starting at 20.00 GMT.