MONTREAL - Top-seeded Novak Djokovic survived two match points in a comeback 5-7, 7-6 (7), 6-1 victory over unseeded Ernests Gulbis in the quarter-finals of the US$4.1 million men's Rogers Cup on Friday night.

In another quarter-final action, unseeded Jeremy Chardy upset 16th seeded John Isner 6-7 (9), 7-6 (13), 7-6 (4).

Djokovic will face Chardy in the semifinals on Saturday. Djokovic is 9-0 in his career against the Frenchman.

"It will be a tough match," said Chardy. "I still never won a set (against Djokovic).

"But I'm confident, and it will be a new match. For sure, I would prefer Ernests, but if I play against Novak, I have nothing to lose. I will go on court and try something new. Anyway, in the worst case I will lose."

Kei Nishikori, fresh from his third win of the season last week in Washington, D.C., was merciless in a 6-2, 6-4 victory over three-time Rogers Cup champion Rafael Nadal. It was Nishikori's first win over Nadal in eight attempts.

"It took a long time to beat Rafa," Nishikori said. "I don't usually like to play against him, but the last couple of matches — I had chances in Australia and in Madrid last year — so I knew I was close.

"Today I was almost dominating everything so I'm very happy."

Fourth-seeded Nishikori was all over Nadal's serve, breaking twice in the first set and twice more in the second while also winning most of the groundstroke duels.

He will face Andy Murray, who beat defending champion Jo-Wilfried Tsonga 6-4, 6-4 in a late quarter-final.

Rainy, muggy weather upset the schedule. Djokovic and Gulbis were to play in the afternoon, but didn't start until the evening.

Gulbis, ranked 87th in the world, took the initiative with an energetic baseline game, won the first set and forced a tiebreak in the second, where Djokovic fought off a pair of match points to turn it around.

It was the first time Djokovic survived match points against him since 2012 in Shanghai against Andy Murray. Gulbis missed a chance for a second career win over a world No. 1 after his victory against Roger Federer in 2010 in Rome.

Chardy staved off seven match points against Isner.

"It was a crazy match," Chardy said.

The Frenchman, ranked 49th, advanced for the first time to the semifinals of a Masters 1000 tournament, one level below the grand slams.

The match began nearly two hours late due to rain.

The six-foot-10 Isner, who won two weeks ago in Atlanta and reached the final in Washington, had won 11 of his previous 12 matches.

After winning a first-set tiebreaker, Isner led 3-1 in the second when play was halted one hour nine minutes by rain. When play resumed, Chardy won three straight game before Isner found the range on his serve.

In the second tiebreaker, Chardy fought off five match points and won it when Isner missed a volley at the net and then hit wide on a service return on set point.

There were two more match points at 6-5 in the third set but that also went to the tiebreaker, where Chardy's only point on 16th seeded Isner's serve was the difference as the American hit a backhand long. Chardy won the next two points on his serve to take the match.

"If you start to think about match points or breakpoints, you start to be nervous," he said. "In this match a lot of points were really important, with a lot of pressure."

Chardy had a relatively easy road to the quarter-finals. His scheduled first round opponent, 11th-seeded Richard Gasquet, withdrew with an illness. Chardy beat qualifier Nicolas Mahut instead, then topped unseeded Leonardo Mayer and Ivo Karlovic. He also survived two match points against Mayer.

In doubles, Toronto's Daniel Nestor and Edouard Roger-Vasselin advanced to the semifinals with a 6-4, 6-2 win over Nenad Zimonjic and Marcin Matkowski.