Nadal, who won his fourth title in Canada a year back, required just about two hours Friday to conquer the Italian veteran who stunned him on clay at Monte Carlo in April.
Rafael Nadal enters Montreal Masters semi-finals after defeating Fabio Fognini by 2-6, 6-1, 6-2.
'It was an up-and-down match, but a positive match for me because I played better and better as it went on,' Nadal said. 'I lost the first set feeling that I was not playing badly. Things were just going too fast.
'Things happen quickly here because the court is fast. Sometimes in the first set, the player who is taking advantage has the adrenaline very high,' he said. 'It's difficult to quickly stop that momentum.'
World number two Nadal was the main significant seed to endure a quarter-final separate after thrashings for Dominic Thiem and Alexander Zverev.
He won't know who he'll play for a spot in the final until Saturday when Gael Monfils and Roberto Bautista Agut come back to finish a downpour postponed match.
Unfaltering precipitation started as Monfils and Bautista took the court and they were not able to complete a game before play was suspended for the evening.
Austrian second seed Thiem, falling off a passionate home triumph in Kitzbuehel a week ago, hit the stopping point in a 6-3, 6-1 whipping on account of Russia's eighth-seeded Daniil Medvedev.
Number three Zverev was not able to establish a connection on Russian 6th seed Karen Khachanov, losing 6-3, 6-3 out of 74 minutes.
Zverev endured the first flaw on what had been an ideal 7-0 record in Montreal after winning the 2017 release in his maiden visit to the city, which interchanges with Toronto as host setting every year.
Khachanov and Medvedev are 1-1 in their competition, having played each other in Moscow last season and in 2017 at the NextGen final in Milan.
'It's never easy to play a good friend, especially from the same country,' Khachanov said. 'Daniil is having a great season. The match will be difficult. He's a dangerous opponent. He has been destroying everyone this week. It should be a great match.'
Two-time Roland Garros finalist Thiem, who had never prevailed upon a match in Canada five years of attempting before this week, said he didn't get an opportunity against Medvedev as a wild sightseeing timetable made up for lost time with him in his 56-minute misfortune.
'With all the traveling and short transition, two very tough matches yesterday and two days ago, I think the battery was empty today. I was not on my 100 percent,' he said.
'This is just not enough in the quarter-finals of a Masters 1000, especially against a guy like Daniil, who is in a great shape, who is playing amazing tennis.' Medvedev admitted he was expecting Thiem to be tougher.
'I was happy that I was able to play so well, to beat him so easily,' Medvedev said. 'It saved me a lot of energy. It gave me a lot of confidence, so I'm very happy.'
