Novak Djokovic shows his emotion after fighting through a three-set duel against Nikoloz Basilashvili at the Qatar Open on Thursday. Photo: Noushad Thekkayil/EPA

DOHA – 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 semi-finals.

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.

It is 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.

He lost his first service game and never recovered the break as Basilashvili, the number five seed, powered by a blistering forehand took the first set.

However, Djokovic’s fortunes changed in the second set when he broke the Georgian in the fifth game, and slowly took control of the match.

Twice a previous tournament winner in Doha, Djokovic now has a 15-1 record overall at the event.

The irrepressible Djokovic is set to play his sixth match of the week later on Thursday when he continues his doubles partnership with his brother Marko.

The other semi-finalists will also be determined on Thursday when Tomas Berdych of the Czech Republic plays France’s Pierre-Hugues Herbert, and Dusan Lajovic of Serbia takes on Italy’s Marco Cecchinato.