Wawrinka remains on course in St. Petersburg

Top seed Stan Wawrinka made short work of Serbia's Viktor Troicki in the quarter-finals of the St. Petersburg Open in Russia.

The Swiss star, fresh from his victory at the US Open, needed just 64 minutes to dispatch his opponent 7-5, 6-2 and set up a semi-final clash with fourth seed Roberto Bautista-Agut of Spain.

Troicki was much more competitive in the first set than the second, holding off Wawrinka for 11 games before finally surrendering a break in the 12th.

Having taken a one-set lead, Wawrinka did not let up in the second, claiming successive breaks in games six and eight to wrap up the comfortable victory.

His semi-finals opponent Bautista-Agut, meanwhile, came back from a set down to defeat Joao Sousa 4-6, 6-1, 6-2.

Roberto Bautista Agut

"He's a great player, a great fighter," Wawrinka said of Bautista-Agut.

"He likes this kind of surface and I'm looking forward to an interesting match."

The other semi-final will see Tomas Berdych of the Czech Republic take on Germany's Alexander Zverev.

Third seed Berdych defeated Paolo Lorenzi 6-4, 6-3, while Zverev was a 6-2, 6-2 winner over Mikhail Youzhny, the man responsible for knocking out Milos Raonic on Thursday.