Turns out the switch actually benefited him in the end.
Djokovic, seeded ninth, cruised past Canadian wild-card entrant Peter Polansky 6-3, 6-4 for a second-round victory in 1 hour, 25 minutes.
It would also raise the hosting standards of the Davis Cup to a Grand Slam level, ITF chief David Haggerty told AFP. It was a little disappointing in that sense. So now I'm going to use it in my favor for my next match against him and try to get the most out of it. It really frustrates me.
Shapovalov fired nine aces and won 82 per cent of his service games in a match that, minus delays, lasted just one hour 22 minutes.
It took a break in each set to do the business, and Djokovic headed, barely breaking out of third gear, into the third round, 6-3, 6-4.
"Whenever I'm at home, I just seem to loosen up with the crowd", Shapovalov said. "So I'll just focus on this week and see how it goes". It's important that I have another match tomorrow too.
"I actually feel like there is more time now than before because the shot clock starts counting down once the chair umpire calls the score", Djokovic said. The Spaniard broke six times, and although he struggled on serve in the second set, losing his serve three times, the outcome was never in doubt as Nadal improved to 4-0 against Paire in their FedEx ATP Head2Head series.
"There were frustrations at times but that means I care".
"I've never played Basic". I'm very pleased, I needed a match like this.
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Four-time champion Novak Djokovic and top-seeded Rafael Nadal advanced to the third round of the rainy Rogers Cup on Wednesday.
Elsewhere, Maria Sharapova made quick work of Bulgarian qualifier Sesil Karatantcheva, easily winning 6-1, 6-2 in a renewal of their former teenage rivalry.
Auger-Aliassime was coming off the biggest win of his career, downing No. 18 Lucas Pouille of France in straight sets on centre court on Tuesday.
Stan Wawrinka and Novak Djokovic reached the second round of the Toronto Masters on Tuesday, with both men polishing their pre-US Open form. 2017 breakout semifinalist Denis Shapovalov rolled through Jeremy Chardy 6-1, 6-4.
Nestor is retiring following the Davis Cup in September.
In Montreal, Alize Cornet of France beat listless-looking Wimbledon champion Angelique Kerber 6-4, 6-1 on in the second round of the Rogers Cup.
Third seed Juan Martin del Potro was forced to withdraw prior to his opening match due to a left wrist injury.
Haase instead faced veteran Mikhail Youzhny, defeating the Russian 7-5, 6-2.
The top eight seeds had gotten a bye to the second round.