Nadal, playing his first match since losing to Roger Federer in the Wimbledon semi-finals, fell behind 5-2 in the tiebreak before roaring back to prevail in his first career meeting with world number 53 Evans.
The Spaniard jumped to a 2-0 lead in the second set before the players were forced off court for a rain delay and when play resumed Evans got back on serve at 3-3 before Nadal regained his confidence and proved too strong.
The French Open champion said he did not make an ideal start as he struggled to adjust to a new playing surface given the amount of time he logged on clay and grass in recent months.
“After Wimbledon always the mind goes down a little bit because I have been playing long claycourt season, then grass, so you didn’t relax,” Nadal told reporters. “Then when you finish Wimbledon, it’s like your body lose a little bit that tension, so it needs little bit of time to recover.
“Today, as I said before, the main thing is win. I know with victories that other things should be coming slowly.”
Up next for Nadal, a four-times champion in Canada who has never successfully defended a hardcourt title in his career, will be Argentine Guido Pella, who was a 6-3 2-6 7-6(2) winner over Moldova’s Radu Albot.
In other second-round action, Frenchman Richard Gasquet upset Japanese fifth seed Kei Nishikori 6-7(6) 6-2 7-6(4) and Croatian 14th seed Marin Cilic was a 6-3 6-4 winner over Australian lucky loser John Millman.
Among the other seeded players seeking third-round spots on Wednesday are Austrian Dominic Thiem, 2018 runner-up Stefanos Tsitsipas of Greece, big-serving American John Isner and Frenchman Gael Monfils.
Italian seventh seed Fabio Fognini will cap the evening session with a match against American qualifier Tommy Paul after an all-Canadian battle between 17th seed Milos Raonic and Felix Auger-Aliassime.
