Ernests Gulbis blasted Canadian fans, calling them "stupid" and saying they conspired against him in his quarter-final loss to crowd favourite Milos Raonic.

"They're used to hockey here, it's okay," Gulbis said of the jeers he received through his 7-6 (7/3), 4-6, 6-4 loss at the ATP Tour Rogers Cup. "But I don't understand why you need to clap for a double fault. There can be emotions, but I think it's stupid.

"I can't call a thousand people stupid. But it's something that I don't understand. That's why all the Canadian players, they play always very well in Canada."

Latvian Gulbis, who is ranked 38th in the world, criticized some of Canada's professional players for only playing well at home and not travelling outside of the country to compete very often. He said world No. 13 Raonic is the exception.

"Honestly some of them - I guess you know who - they don't play really (well) nowhere else," the 24-year-old Gulbis said without naming names.

"Milos is a great player. But the rest of the guys, they play great in Canada because it's like Davis Cup every match. People are clapping after a double fault, before a second serve to provoke a double fault. I don't think it's nice.

"The crowd is very well educated. They know exactly what to do in the right moment to screw up the other player's game."

Gulbis wasn't especially pleased with his effort on the court. "The feeling is bad. I don't know if the match was very interesting to watch. Maybe it was interesting because of the emotions, there were a lot of tight points.

A record five Canadians made the second round in Montreal. Raonic's win sets up an all-Canadian semi-final featuring Raonic against Vasek Pospisil.

It will be the first meeting between Raonic and Pospisil in an ATP Tour tournament.