mGervonta Davis knocked out Ryan Garcia with a withering body shot in the seventh round of their eagerly awaited summit meeting on Saturday night, delivering a signature performance in the year’s most anticipated fight that conferred his status as the face of American boxing.

The 28-year-old three-division champion from Baltimore sent Garcia to the canvas in the second round before finishing him off in the seventh with a perfect uppercut to the ribs before a capacity crowd at the T-Mobile Arena along the Las Vegas Strip.

Related: Gervonta Davis knocks out Ryan Garcia in seventh round – live

“I remember coming up in the Golden Gloves and seeing [Floyd Mayweather Jr] fight at the MGM,” Davis said. “It was crazy. I actually just saw Rihanna perform at the Super Bowl, and I thought that’s going to be me one day. And we’re here.”

The showdown between two unbeaten American knockout artists early in their primes, represented by warring companies and broadcasters, was one of the biggest matches that could be made in boxing today. It managed to live up to the considerable hype, with moments of two-way drama in the opening stages lifting the divided crowd into frenzy until Davis’s overall class won out.

No titles were on the line in the scheduled 12-round bout, which took place at a catchweight of 136lbs, but the stakes could hardly have been higher. Already an emerging mainstream attraction, Davis moves forward as the sport’s biggest star in the United States with all the benefits, bragging rights and earning potential that entails, even as he faces the prospect of jail time stemming from a November 2020 hit-and-run in less than two weeks’ time.

“I’m definitely the face of boxing,” Davis said. “Absolutely.”

Garcia (23-1, 19 KOs), the 24-year-old from Orange County who lives in Los Angeles, was fast out of his corner and aggressive from the opening bell, throwing jabs and straights to the head and body while pressing his advantages of four and a half inches in height and two and a half inches in reach. Davis, a southpaw endowed with concussive power in both hands known for overcoming quiet starts with a deliberate stalking style, barely threw a punch in the first three minutes while patiently taking his opponent’s measure.

Davis (29-0, 27 KOs) appeared to be hurt early in the second after Garcia landed a combination along the ropes that whipped the audience into a frenzy. But that’s when Davis caught his foe with a punishing counter left upstairs against the run of play that dumped Garcia to the seat of his trunks and brought the crowd of 20,842 spectators to their feet.

“I thought I had him pretty hurt to be honest,” Garcia said. “But that’s what I get. I was impatient and I got caught. I ran into an overhand left.”

Garcia appeared sturdy after beating the count, made it to the bell and continued to press to open the third round undeterred, but he was that much more hesitant after tasting Davis’s notorious power. By the fourth, Davis was backing up Garcia steadily in a complete reversal from the opening minutes. His unpredictable array of feints and upper-body movement kept Garcia off balance and reactive into the fifth and sixth, where the gulf in skill and experience between the pair became even more evident.

Then came the seventh, when Davis detonated a straight left hand on Garcia’s midsection in the center of the ring that sent his foe reeling backward into a neutral corner and down to his right knee. He remained there as referee Thomas Taylor picked up the 10-count, then waved it off when Garcia didn’t make it to his feet in time at the 1:44 mark.

“I couldn’t breathe,” said Garcia, who connected on 39 of 164 shots (23.8%) compared to 35 of 103 for Davis (34.0%), according to Compubox’s punch statistics. “I don’t want to make no excuses in here. I just couldn’t recover and that’s it. He caught me with a good body shot, snuck underneath and he caught me good.”

Davis has moved the needle like few other American boxers in recent memory, winning belts at 126lbs, 130lbs and 135lbs while selling out arenas from coast to coast. But while the Marylander’s professional resume held up better than Garcia’s to close scrutiny, the plain fact was each man was still in search of a defining win and was in with the best opponent of his career on Saturday night. It was a risky proposition for both fighters and one that paid off handsomely for Davis in a long-awaited grudge match preceded by nearly two years of trash talk and ill will.

“I know we talked a lot of trash leading into the fight, but (Davis) knows what it is,” Garcia said. “It’s all love at the end of the day. I was honored to be in the ring with a great fighter and I respect him a lot.”

Davis’s win could set the stage for a lightweight showdown with Devin Haney, who holds all four major title belts at 135lbs and faces Vasiliy Lomachenko next month. But his immediate future is up in the air after he entered a guilty plea in January to four counts stemming from a hit-and-run which left four people hospitalized, including a pregnant woman. After the judge overseeing the case rejected a plea deal that would have allowed him to serve 60 days of unsupervised home detention, Davis faces the real prospect of jail time at his sentencing on 5 May.

But for now, Davis can bask in the glow of his career-best triumph after further building on the promise first announced six years ago, when he became boxing’s second-youngest world champion at just 22 years old.

“The reality definitely matches the dream,” Davis said. “But the job is never done until I retire so I’m going to keep my head down, stay humble and continue to work.”