Qualifier Zverev stuns Wawrinka in Swiss quarters

Three times Grand Slam winner and 2016 US Open champion Stan Wawrinka was stunned 6-2, 5-7, 6-1 by qualifier Mischa Zverev in the quarterfinals of the Swiss Indoors event at Basel.

Mischa Zverev reached the semifinals of Swiss Indoors event after beating local favourite and top seed Stan Wawrinka. Aly Song/Reuters

The 72-ranked Zverev now faces Croatian fourth seed Marin Cilic, who beat Spain's Marcel Granollers 6-3, 6-3, for a place in the final.

After losing the first set, Wawrinka staged a comeback by winning the second. However, he had no answer to Zverev’s attacking play in the decider as he went down a double break on his way to defeat in just under two hours.

“Zverev almost beat Novak Djokovic two weeks ago in Shanghai,” Wawrinka said. “He is an offensive player who likes to rely on the speed of the ball from the opponent.”

In the other semi-final, Kei Nishikori faces Gilles Muller. Nishikori overcame the challenge of two-time winner Juan Martin del Potro 7-5, 6-4 while Muller had to endure tough resistance from Federico Delbonis, with the Luxembourg player eventually prevailing 6-7 (4/7), 6-4, 7-6 (7/3) winner over Argentine Federico Delbonis.

“This was my best match of the week," said Nishikori. “It was a tough match. I had so many chances, so many break points, that I could not convert."

Murray marches into Vienna semis

Meanwhile, world no 2 Andy Murray defeated John Isner to reach the Vienna semi-finals.

Murray, the 2014 champion in the Austrian capital, cruised to a 6-1, 6-3 win claiming his 68th win of 2016 and extending his unbeaten streak to 14 matches.

Murray needs to win the Vienna title on Sunday, as well as next week's Paris Masters, to have a chance to knock Novak Djokovic off the world top spot.

Murray now faces defending champion and fifth seed David Ferrer who saved a match point to beat Serbia's Viktor Troicki 6-3, 3-6, 7-5.

Ivo Karlovic too saved a match point to defeat Karen Khachanov 6-7 (5/7), 7-6 (7/5), 6-3 to reach the semi-finals.

Karlovic will next face sixth seed and 2011 champion Jo-Wilfried Tsonga, who got the better of Albert Ramos-Vinolas in straight sets.