NEW YORK

Conor McGregor raised his arms in triumph before he stepped inside the cage, the cocky Irishman playing to a crowd going wild for UFC’s greatest champion.

McGregor ran a circle around the mat, a victory lap of sorts before he even threw a punch. McGregor packed fans to the Madison Square Garden rafters and drove them into a frenzy as he packed a vicious punch against Eddie Alvarez.

McGregor used a brash and brilliant performance to knock out the overwhelmed Alvarez in the second round to win the UFC lightweight title Saturday in the main event of UFC 205 on a record night.

He dubbed himself this week the King of New York.

Now, he’s been crowned a two-class champ.

“What’s next for me,” McGregor bellowed inside the cage.

The easy answer: whatever the “Notorious” one wants.

McGregor dominated from the opening bell of the biggest card in UFC history — on pace to set an MMA pay-per-view record — and the sold-out crowd of 20,427 loaded with A-listers from Madonna to Hugh Jackman went wild with each punishing blow.

McGregor, also UFC’s featherweight champ following a 13-second knockout of Jose Aldo, had predicted a fourth-round KO.

Unlike UFC’s laborious legal fight to reach New York, McGregor wouldn’t make anyone wait.

UFC has not decided if McGregor (21-3) will be allowed to defend both championships. UFC President Dana White said McGregor could be about the only fighter in the promotion to handle that kind of grueling fight load.