Tokyo - Defending champion Kei Nishikori survived a war of attrition against Croatia's Marin Cilic to reach the Japan Open semi-finals on Friday, winning a cliff-hanger 3-6, 7-5, 6-3.
Top seed Stan Wawrinka overpowered American qualifier Austin Krajicek 6-3, 6-4 to join him in the last four, though the Swiss required less than an hour to take care of business on a sunny afternoon in Tokyo.
Second seed Nishikori was greeted like a rock star by 12,000 screaming fans but Cilic, who beat Japan's golden boy in last year's US Open final, had failed to read the script and quickly seized the initiative with some thunderous hitting.
Serving with such ferocity he knocked the racquet out of Nishikori's hand, the sixth seed broke first with a thumping forehand drive to lead 4-2 before wrapping up the opening set with an ace down the centre.
Bidding for his third Japan Open in four years, Nishikori hung tough in the second set and, as cracks began to appear in Cilic's armour, levelled with an acrobatic leaping backhand that his opponent could only dump into the net.
Cilic's game unravelled under the onslaught in the decider as Nishikori caught fire, breaking for 3-1 and closing out the quarter-final with an ace after two hours, 11 minutes.
World number four Wawrinka's path to the final was made easier when third seed Gilles Simon of France crashed out 6-3, 6-4 to Luxembourg's Gilles Muller.
Wawrinka made no mistakes as he powered past Krajicek in just 58 minutes, and the left-hander had no answer to the rapier-like ground strokes of the French Open champion.
Wawrinka's one-handed backhand - one of the most venomous shots in men's tennis - did much of the damage and he closed out the match with a kicking serve which a deflated Krajicek swatted wide and long.
"I felt a bit more relaxed today and confident with my game," said Wawrinka, who is chasing his fourth title of the year and the 11th of his career.
"A one-hour match, it was the perfect day for me today."
Controversial Australian Nick Kyrgios, still looking for the first tournament victory of his fledgling career, was scheduled to play Frenchman Benoit Paire in Friday's late match for the right to meet Nishikori in the semi-finals.