Rafael Nadal won his 80th ATP World Tour title and spoiled the 20th birthday celebrations of Stefanos Tsitsipas.
The top-ranked Nadal beat the unseeded Greek 6-2 7-6 (7-4) for his fourth Canadian Open crown and fifth title of the year.
He has a record 33 ATP World Tour Masters 1000 titles - his first since Cincinnati in 2013.
"If you told me this two weeks ago I would not have believed it," Nadal said.
"It's a great way to start the hard-court season.
"Winning in Toronto is so important. You don't win Masters 1000s very often.
"It's a very important victory for me and I'm very happy.
"It has been a fantastic week, a very positive one."
The 32-year-old Spaniard later announced that he would skip the Masters tournament in Cincinnati this week to rest and get ready for the US Open, which begins on August 27.
"No other reason than personally taking care of my body and trying to keep as healthy as I feel now," Nadal said in a statement.
And so a "Big Four" reunion will have to wait for at least a few more weeks.
Nadal, Roger Federer, Novak Djokovic and Andy Murray haven't played in the same tournament in more than a year. The other three are scheduled to play in Cincinnati this week.
Nadal's Toronto win was notable.
His previous four titles this year came on clay at the French Open, Monte Carlo, Barcelona - where he beat Tsitsipas in the final - and Rome.
"He was normal like all of us and he managed to become this beast, this monster that he is today," Tsitsipas said.
"It's true ... that's how you feel when you play against him. I need to work much more and hopefully I can reach his level one day."
Nadal overcame a late service break when serving for the match and fought off a set point before he converted his first match point of the tiebreaker.
"He never cracks," Tsitsipas said.
"He will always grab you like a bulldog and he will always make you suffer on the court."
Tsitsipas reached the final by becoming the youngest player to beat four straight top-10 players in an event since the ATP World Tour was established in 1990.
He will jump from 27th to 15th in the world on Monday.