Djokovic, playing his first match since his shock third-round Wimbledon loss to American Sam Querrey, fell behind 3-1 in the tie-break before switching gears and winning the next six points to seal the win in one hour, 43 minutes.
"It's tough playing the first hardcourt match since March. It was hot and that made the ball move very fast," said Djokovic. "It was hard to control, it was not easy to play. But I managed to stay tough."
The Serbian world number one, a three-times winner of the Canadian Masters event, will next play Czech qualifier Radek Stepanek, a 7-6(5) 6-4 winner over Canadian wildcard Peter Polansky.
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Querrey, whose Wimbledon run came to an end with a quarter-finals loss to eventual runner-up Milos Raonic, could not pen a similar script as he retired from his second-round clash with Belgian seventh seed David Goffin while trailing 6-4 2-1.
Japanese third seed Kei Nishikori beat American qualifier Dennis Novikov 6-4 7-5, ninth seed John Isner fell 7-6(3) 6-7(4) 6-4 to American Ryan Harrison and Canadian fourth seed Raonic beat Taiwan's Lu Yen-hsun 6-3 6-3.
For Raonic, who grew up in a Toronto suburb, the match was his first since losing the Wimbledon final to Britain's Andy Murray and he soaked up the warm reception from fans.
"I don't get to play here in Toronto very much," Raonic said. "I can't wait to come back out here tomorrow."
(Reporting by Frank Pingue, editing by Ed Osmond/Greg Stutchbury)
