Mixing sublime touch with ferocious firepower, Popyrin out-gunned volatile Russian world No.6 Andrey Rublev 6-2 6-4 in thunderous final triumph in Montreal.
The 25-year-old pocketed a monster cheque for $US1.05 million ($A1.6 million) after becoming the first Aussie to win a Masters 1000 event since Lleyton Hewitt went back-to-back in Indian Wells while world No.1 in 2002-03.
"It means so much. It means the world," Popyrin said.
"All the hard work that I've put in over the last few years. All the sacrifices that I've made, not just me but my family, my girlfriend, my team, everybody around me.
"They've just like sacrificed their lives for me and for me to win this for them is just amazing."
Alexei Popyrin slaps a forehand down the line against Andrey Rublev. (AP PHOTO)
In claiming five consecutive top-20 scalps for the week, Popyrin also slashed his ranking from 62nd to world No.23 and secured a precious first-time grand slam seeding for the US Open starting in 13 days.
Popyrin had beaten last week's Washington title winner Sebastian Korda in the semi-finals after earlier upsetting fourth seed Hubert Hurkacz in the quarters in one titanic day.
He also took out 11th seed Ben Shelton and saved three match points against seventh seed Grigor Dimitrov in round three.
The former French Open junior champ's last defeat came against eventual champion Novak Djokovic at the Paris Olympics.
But in making a superb transition from clay to hard courts, the lowest-ranked Montreal finalist since Harel Levy in 2000 displayed few signs of nerves under the bright lights on Court Central.
Rublev had ousted top-seeded Australian Open champion Jannik Sinner in the quarter-finals and was chasing a 17th career title of his own.
But it was Popyrin the underdog who set the tone with a blazing start.
He opened the match with a scorching forehand return winner and broke Rublev to love.
The Russian's volcanic temper was immediately evident when he furiously cursed himself after coughing up successive double-faults to gift Popyrin the break.
Andrey Rublev loses his temper during the Montreal Masters decider. (AP PHOTO)
Popyrin consolidated then conjured three aces to recover from double break-point down in the fourth game to hold before forging to a 4-1 lead with a second service break.
He brought up set point with an outlandish 167kph off-forehand winner and promptly wrapped it up after just 35 minutes.
The Sydneysider was motoring to the finish line after nabbing a third service break in the second game of the second set, then having a point for a double break.
Popyrin could have blinked, or even folded, after dropping serve for the first time to allow Rublev back into the contest at 3-3.
Instead he broke straight back with another massive forehand winner.
Even after losing a lung-busting 25-shot rally, Popyrin rebounded immediately with his 10th ace to earn match point.
Rublev saved two but not a third as Popyrin improved to a perfect three from three in finals to add the Montreal title to his 2021 breakthrough in Singapore and 2023 title in Umag, Croatia.
Monster forehand 🔥— ATP Tour (@atptour) @AlexeiPopyrin99 | @OBNmontreal | #OBN24 pic.twitter.com/3eVK5sSePuAugust 13, 2024
With Alex de Minaur falling to Sinner in last year's final, Popyrin is the first Australian to win the Canadian Masters since Pat Rafter in 1998.
Barely three weeks later, Rafter won the US Open at age 25.
Popyrin will be hoping that's an omen.
The vanquished Rublev could only tip his hat to the champion.
"I would like to congratulate Alexei for amazing week and his team for amazing effort. He beat really great players," he said.
"He was having a really tough draw, finishing last night really late and then won the title.
"It's a really big achievement."
