Novak Djokovic pleased with "challenging" win

Novak Djokovic has admitted that his semi-final win over Juan Martin del Potro at the Dubai Championships was "challenging".

The world number one took the first set 6-3 against the Argentine before edging through a second-set tie-break 7-4.

"His serve is very powerful," said Djokovic. "His forehand from the back of the court he can do anything with - I needed to stay in it when I was a break down.

"I played a poor game when I needed to close it out but he's a great player, so it was always going to be challenging."

Djokovic will take on third seed Tomas Berdych in Saturday's final following the Czech's surprise victory over Roger Federer.