Floyd Mayweather extended his perfect career record to 50 fights unbeaten by stopping Conor McGregor in the 10th round of one of the richest fights in boxing history.
At a packed-out T-Mobile Arena in Las Vegas, the former five-weight world champion faced flurries of early punches from UFC's most iconic figure, who was making his debut in professional boxing.
McGregor delivered a crisp uppercut in round one and, though he edged close to breaking rules with several punches to the back of the head, he imposed himself admirably without ever looking as though he would knock out Mayweather.
The American, who came out of retirement for a potential $300m pay day, executed a gameplan which pounced on McGregor's lack of conditioning for the late rounds which prove so key on big fight nights.
As tiredness took hold, Mayweather upped his ferocity. By round nine the 40-year-old began to stalk McGregor, whose legs were weakening as his rival fired - and landed - more.
And in the 10th, again near the ropes and with the Irishman offering little, the fight - which followed weeks of manic build-up, spiteful words and chaos - was over.
Referee Robert Byrd's stoppage may have arrived too early for some, as McGregor's early effort meant he was in the contest on the scorecards.
But the 29-year-old was wilting and, though his effort and display should be commended, Mayweather's poise and invincibility remains constant.
Relive Mayweather's victory over McGrego