MIAMI GARDENS, Fla. -- The gunmetal clouds filtered out the sun, leaving Felix Auger-Aliassime and his opponent, Hubert Hurkacz, bathed in tawny sunlight on Court 1 on a mellow Sunday afternoon at the Miami Open. The palm fronds reaching above the court swayed gently like sea fans. But Auger-Aliassime wasn't feeling the mellow.

Serving but trailing love-30 at 3-4 in the first set, he looked like a hunted man. He had been questioning line calls, throwing gestures of futility toward the friends and family section and shaking his head in disgust.

Then, in succession, Auger-Aliassime played four points that demonstrated why the 18-year-old Canadian -- the only teenager in the Miami Open men's singles draw -- is becoming a sensation. They were a ferocious swinging volley winner, an unreturnable drop shot off a service return (played as if the ball were an egg), a leaping backhand, overhead putaway and a game-ending, thumping ace.

"I'm pretty instinctive. I try to do the best decision at any given moment," Auger-Aliassime told ESPN.com not long after his 7-6 (5), 6-4 third-round win over Hurkacz, a gifted 22-year-old who was coming off an upset of No. 3 seed Dominic Thiem in the second round of the Miami Open. "But [the game] goes so fast that you just have to trust your instincts."

Auger-Aliassime's instincts are not only reliable, they're also bundled in an impressive package. "FA2" is 6 feet, 4 inches of muscle so lean and free of fat that almost any physical motion sends a ripple through his skin. He's cat-quick and crushes the serve and forehand, but lots of guys do that. What sets him apart is the aura of control that informs his game. He's instinctive but not impulsive, explosive but not reckless, aggressive but not injudicious.

Sure, he can pull long faces or express his frustration with line calls. But few players regain their physical equilibrium after losing a point or reset after missing a serve as quickly as FA2 does. He'll whirl around and gesture for a towel after driving a ball into the net, then fall utterly still before it's delivered. He reverses the usual trope, going from 60 to zero in nothing flat, a sign of great discipline.

That constraint was developed under the guidance of his father, Sam Aliassime, who emigrated from Togo and married French Canadian schoolteacher Marie Auger. Sam and Marie have two children, Felix and a younger daughter, Malika. Sam wanted his children to have both parents' names to pay homage to their dual heritage, and Auger-Aliassime has said he wants to keep it that way.

Fortunately for the game of tennis, there was never any danger of losing Felix to that great thief of Canadian athletic talent, hockey. "My mom isn't a sports fan, and my dad didn't know what hockey was until he got to Canada," Auger-Aliassime said, adding that he grew up to become a hockey fan (Les Habs, of course). "Our parents wanted me to be a complete athlete, so we played all sports, but tennis always was at the top."

His father took Felix's game as far as he could, which was basically until his son turned 13. At that point, Felix began to train with the elite coaches and players at the National Training Centre in Montreal. "It was a big difference from before," he said. "Suddenly, I'm seeing good players like Milos [Raonic] and Vasek [Pospisil]. From that point, I really got to another level. That's where you go from being a player with good potential to someone who can win junior tournaments, and it can get you to the pros."

Felix Auger-Aliassime's control might be the most impressive part of his game -- but he's not above a little emotion as well. AP Photo/Jim Rassol

With a teacher for a mother (Marie teaches child psychology), Auger-Aliassime also learned to value education. He made a pact with his parents: "I would finish high school with good grades, and then, depending on where my level in tennis was, either go to university or go pro."

The frat houses never had a chance. Auger-Aliassime won the US Open junior title in 2015 at age 15. He was soon carving up the Challenger circuit, winning one at age 16 and one at 17. He made a breakthrough at the pro level in 2018, when he made the main draw at Indian Wells and enjoyed a bittersweet win over a friend and something of a role model, Pospisil.

Auger-Aliassime qualified for the 2018 US Open as well and had the bad luck to draw as his first opponent his close friend and compatriot, fellow prodigy Denis Shapovalov. Shortly after the two split sets, FA2 was forced to retire with heart palpitations -- thankfully, they were caused by the extreme heat, not a more threatening condition.

Auger-Aliassime has continued his steady upward arc this year. He became the youngest finalist at an ATP 500 tournament in February in Rio, with a performance that shot his ranking up to No. 60. He celebrated soon thereafter with his first win over a top-10 player when he knocked off Stefanos Tsitsipas in the second round at Indian Wells. The win was built on FA2's appetite for attacking tennis. "I prefer attacking tennis to baseline tennis," he said. "I try to attack. It's how I was raised to play."

After taking that loss, Tsitsipas told the press, "When I was returning close from the baseline, I didn't feel that much control of my ball. And he was hitting, I mean, so hard that I had to take some time and be well-prepared for the next shot. It felt like he was taking the balls very early and didn't give me much time."

"I try to attack. It's how I was raised to play." Felix Auger-Aliassime

Auger-Aliassime put Sunday's win over Hurkacz above even that one, though it's less gaudy. Hurkacz is ranked No. 54, but he's 6-foot-5 and an excellent mover. He's also from Poland and flying well under the radar.

"Maybe I dominated a little more against Stefanos, and he's higher ranked, but this was my best match yet," Auger-Aliassime said. "The level of tennis overall was better today, and the crowd enjoyed it as well. It was a lot of fun to be part of it."

It's hardly surprising to get that kind of aesthetic judgment from a soft-spoken young man who says that if he were to choose a different path in life, he would become an artist. The fans have taken a shine to FA2, and he gets on famously with Shapovalov. He feels lucky to be part of what appears to be a magical time for Canadian tennis.

"The success we're having motivates us, and we like seeing each other do well," Auger-Aliassime said. "We do have to compete against each other, but we still follow each other's results, and seeing Bianca [Andreescu] doing so well now too, it's really inspiring. It isn't just me and Denis [Shapovalov]. There are other kids coming."

It's refreshing to hear an 18-year-old who will soon be a legitimate Grand Slam contender speak so warmly and encouragingly of potential rivals in an era chock-a-block with callow athletes who live in bubbles with just a few team or family members. FA2's open, friendly nature will serve him well -- almost as well as that instinctive decision-making and the exceptional control he has over his mind and body.

On match point for FA2 on Sunday, the two sluggers had a brief rally. Hurkacz looped a mishit forehand that seemed to be heading out, which led to the beginning of a celebration by Auger-Aliassime. But there was no out call. FA2 froze as he raised his hand to challenge the non-call. In the precious moments before Hawkeye rendered judgement, FA2 was on one knee with a pleading look on his face. When the screen confirmed that the ball was out, he leaped up, bellowing, with an ecstatic smile on his face.

Sometimes, it's OK to totally lose control.