Djokovic battles thru'

World number one Novak Djokovic won another gruelling battle in Doha on Thursday to continue his unbeaten start to the year and progress to the Qatar Open semifinals.

The Serb came from a set down, just like in his previous match, to beat Georgia's Nikoloz Basilashvili 4-6, 6-3, 6-4 in a match lasting almost two hours.

Djokovic will play Spain's Roberto Bautista Agut in Friday's semi-final, who beat three-time Grand Slam winner Stan Wawrinka in straight sets 6-4, 6-4.

And, ominously, for his opponents said he still plenty of room for improvement.

"I feel I have a gear or two (to go) up still," said Djokovic.

"Under the circumstances I managed to find a way to win against a player that is hitting the ball very fast and just being very aggressive and it's hard to predict where the ball is going to go with a player like him."

It was the first time Djokovic has won back-to-back matches from a set down since Cincinnati in August last year, a tournament he went on to win.

As on the previous evening, where he struggled against Hungary's Marton Fucsovics, the Serb started slowly.