Dubai Tennis Championships: Novak Djokovic bolts into semi-finals; Stefanos Tsitsipas comes from set down to beat Jan-Lennard Struff

Novak Djokovic celebrates after he beats Russia's Karen Khachanov during a quarter-final match of the Dubai Duty Free Tennis Championship. AP[/caption]In all, Djokovic sent down 19 winners to Khachanov’s nine, won 89% of his first serve points, nine of 11 forays to the net, and wrapped up the one-sided affair in just 66 minutes.Time and again he bamboozled his hapless opponent with delicate, wonderfully disguised drop shots, leaving the Russian either flat-footed at the back of the court or sprinting frantically to the net in vain.Khachanov was 5-2 down in the second set and trailing 30-15 when he finally managed to win a point after chasing down a Djokovic drop shot. The 23-year-old celebrated like he had won the match, raising his fists in the air, much to the delight of the crowd.Three points later, Djokovic had sealed the victory.“Tough match for Karen,” the Serb said in an on-court interview. “I think he can do much better than he has done tonight. It wasn’t his day, but on my side I think I played a very solid match.”Djokovic set up a semi-final against third-seeded Gael Monfils, against whom he has a 16-0 head-to-head record.Monfils, though, is on a career-best 12-match winning streak after two straight tournament titles. He kept up his strong form by beating fellow Frenchman Richard Gasquet 6-3, 6-3 in his quarterfinal.Second seed Stefanos Tsitsipas bounced back from losing the first set to Jan-Lennard Struff to claim his spot in the semis with a 4-6 6-4 6-4 victory over the hard-hitting German.The Greek will face Dan Evans for a place in Saturday’s final.Evans, the British No. 1 and world No. 37, beat Russia’s Andrey Rublev 6-2 7-6(9) earlier in the day to record his fifth victory of the year over a top-20 player as he reached the first ATP 500 semi-final of his career.“It sounds a cliché but it’s stay in there and I knew I’d get my chances,” Evans said.“I’m very happy how I played. Staying calm is key to everything really. Getting the balance, you can’t be calm and dull, you’ve got to be aggressive... and stay cool as well.”