Joshua walked to the ring first and received a mixed reception inside the 20,000-seat arena. His expression was stern, reflecting his insistence all week that he would treat the contest seriously.
Paul’s ringwalk raised eyebrows as he was flanked by rapper 6ix9ine, a controversial figure with a history of criminal convictions and prison time.
When the opening bell rang, Paul circled on the back foot and boos soon followed.
Joshua stalked him, swinging heavy lefts and rights that cut only air, with each miss drawing gasps from the crowd. Paul responded by sticking out his tongue, playing to the theatre.
Every passing minute felt like a small victory for Paul, who just 13 months earlier fought 58-year-old Mike Tyson.
He did land a looping overhand right in the fourth, but it barely registered with Joshua.
The event was broadcast live to more than 300 million Netflix subscribers.
Golf superstar Rory McIlroy, fresh from his Sports Personality of the Year win, sat ringside alongside rappers Rick Ross and Timbaland.
The fifth round delivered what many had expected far earlier. A right hook brushed Paul’s shoulder and sent him to the canvas.
Moments later, a combination dropped him again. He rose heavily and was breathing hard as he attempted to mask the damage with bravado.
Another heavy right in the sixth sent Paul sprawling once more, prompting calls from sections of the crowd for the referee to step in.
Those who remembered Joshua’s brutal one-punch knockout of former UFC heavyweight champion Francis Ngannou earlier last year sensed a familiar ending approaching.
It was not quite as savage, but the straight right – the punch Joshua had been waiting for all night – finally landed flush.