The Dubliner defeated Eddie Alvarez in two rounds
Conor McGregor has made history by becoming the first consecutive two-weight champion in UFC history.
The reigning featherweight champion outclassed Eddie Alvarez in Madison Square Garden to add the lightweight belt to his ever-growing collection.
Alvarez did excellently to survive the opening round. Having been knocked to the ground inside 90 seconds, the Philadelphia fighter fell twice more before the first bell.
Referee John McCarthy stopped the fight midway through the second round, after Alvarez fell once more, in what was a one-sided performance.
In a fight of the year contender, Tyron Woodley retained his UFC welterweight title after a majority draw against Stephen 'Wonderboy' Thompson.
After a 47-47 47-47 48-47 result in favour of the champion, the fight was originally given to Woodley, before corrected as a draw.
The fourth round will go down as one of the best in the history of the UFC. Having survived two knockdowns, Thompson escaped a guillotine choke, to end the round on top. Both men, are expected to fight once more very soon.
Karolina Kowalkiewicz, right, and Joanna Jedrzejczyk. (AP Photo/Julio Cortez)
In the all-Polish strawweight title fight between the champion Joanna Jedrzejczyk and Karolina Kowalkiewicz, the champion remained unbeaten in the toughest test of her career.
Having fought each other in the Polish amateur ranks, Jedrzejczyk looked comfortable in the opening three rounds, before struggling in the fourth. Having struggled in the penultimate round, Jedrzejczyk won the last to win 49-46 on all three judge's scorecards in her fourth title defence.
Khabib Nurmagomedov continued his unbeaten streak with a dominant win over Michael Johnson. The Russian won by a third round submission, to move to 24-0.
After his win, Khabib demanded a lightweight title shot, against either Alvarez or McGregor, much to the annoyance of the loud Irish crowd in attendance. "I want to stay humble but I have to talk", he said in the octagon before turning his focus to McGregor. "Ireland only has 6 million people, Russia has 150 million. I want to fight your chicken! Let’s go! Let’s go!"
Khabib Nurmagomedov, top, punches Michael Johnson. (AP Photo/Julio Cortez)
In the featherweight division, Frankie Edgar defeated Jeremy Stephens by unanimous decision. The former lightweight champion won 30-27, 30-27, 29-28 in one of the best fights of the night.
In an excellent second round, where both men could have stopped the fight, Edgar survived what would have been the first stoppage of his career. He also revealed he was injured in the buildup to the event. "I actually tore my MCL and had to get an epidural in my back but nothing was going to stop me from fighting in New York City".
Cuba's Yoel Romero got the better of former middleweight champion Chris Weidman with a third-round knockout. A knee to the New Yorker's head, followed by a flurry of punches gave Romero the win.
After the win, Romero challenged champion Michael Bisping to defend his title next against the 'Son of God'.
There were also a surprise win in the women's bantamweight division for Raquel Pennington. In a one-sided win over former champion Miesha Tate, 'Cupcake' announced her retirement in the ring after the loss.