REUTERS: Daniil Medvedev and Karen Khachanov crushed second seed Dominic Thiem and third seed Alexander Zverev respectively to set up an all-Russian semi-final at the Rogers Cup in Montreal on Friday.
Later in the day, top seed Rafa Nadal overcame a sluggish start to defeat Fabio Fognini 2-6 6-1 6-2 to keep his title defence alive.
The Spaniard and will face either Gael Monfils or Roberto Bautista Agut, who will close out the action under the lights at IGA stadium.
The French-speaking Medvedev was cheered on by a partisan crowd and finished off a tired-looking Thiem 6-3 6-1 to end the Austrian's six-match winning streak in under an hour.
So dominant was the tall Russian that he took the first five games of the second set while winning 16 of the first 17 points.
He missed a chance to close out the match on Thiem's serve at 5-0 before sealing victory with an ace, his sixth of the day.
Medvedev said he was as surprised as anyone to have defeated world number four Thiem in such dominant fashion.
"I was expecting a tougher match," he said.
"I was happy that I was able to play so well, to beat him so easily. It saved me a lot of energy. It gave me a lot of confidence so I'm very happy."
Khachanov had little more problem with German Zverev, rattling through their quarter-final 6-3 6-3 in 74 minutes.
NADAL BATTLES BACK
Nadal initially had a more tricky time in his quarter-final against Fognini, struggling with his serving accuracy in a first set where the Italian broke him twice.
But Nadal broke to love in the second game of the second set on a double fault by Fognini, who appeared to be bothered by right ankle soreness as the nearly two-hour match wore on.
Nadal broke serve to start the deciding set and never looked back as he took a measure of revenge against Fognini, who defeated Nadal in the final of the Monte Carlo Masters in April.
The Spaniard said the key to getting back into the match had been staying in the moment.
"I lost 6-2, things went quick," he said.
"I started the second set thinking I was not playing bad, just things went so quick and everything against me," he said.
"I just tried to be there, to be focussed and to calm down a little bit the match because things were going too quick."
(Reporting by Gene Cherry in Raleigh, North Carolina and Rory Carroll in Los Angeles; Editing by Ken Ferris)