(Reuters) – Japan’s third-seeded Kei Nishikori came from 2-5 down in the opening set to stun Swiss second seed Stan Wawrinka 7-6(6) 6-1 in the semi-finals of the Rogers Cup in Toronto on Saturday. Wawrinka, a two-times grand slam champion who has won 14 ATP World Tour titles, became increasingly dispirited as he lost 11 of the last 13 games at the Aviva Centre after squandering four set points in that opening set. Nishikori, serving at 40-0, sealed victory on the first of his three match points when an overhead smash prompted an unforced error from his opponent, ending an encounter that lasted just under an hour-and-a-half.