UFC 292: O'Malley stuns Sterling with second-round KO to claim bantamweight title

In the co-main event, Zhang Weili retains strawweight title with a thrilling points win over Amanda Lemos

Sean O’Malley lands the punch which led to his stoppage win over Aljamain Sterling at UFC 292. Getty

Sean O’Malley lived up to the ever-increasing hype by knocking out champion Aljamain Sterling with a stunning punch in the second round to claim the UFC's bantamweight title at UFC 292 in Boston.

After a cagey opening round, American O’Malley (17-1) dropped Sterling with an overhand right early in the second. With Sterling on the mat, O’Malley hammered the defending champion with left hands to the head until referee Marc Goddard stopped the fight 51 seconds into the round.

"This was the most nervous I've ever been for a fight," said O'Malley, who was fighting in a championship five-round bout for the first time.

"Aljamain is the best bantamweight of all time, so yeah, I was nervous, but I never lost the confidence because I know what I possess: this right hand."

The defeat moved 34-year-old Sterling's professional MMA record to 23-4, which included 10 straight victories heading into the bout with O'Malley. Sterling, from New York, was making the fourth defence of his bantamweight title.

The first round was fairly uneventful, Sterling attempting a takedown with 30 seconds left and pinning O’Malley against the fence before the round ended.

A frantic start to the second round sparked the fight into life as Sterling tried to stalk his opponent, but when he overreached to land a punch, O'Malley countered with a flush right hand to put his fellow American on the canvas. From there, he rained punches down on Sterling until the referee stepped in to end the fight.

Now champion, O'Malley continues his meteoric rise through the UFC ranks and now has the belt to complement his enduring popularity and marketability.

In the co-main event, Zhang Weili of China retained her strawweight title with a thrilling five-round unanimous decision against Amanda Lemos of Brazil. The scores were 50-43, 50-44 and 49-45.

Zhang (24-3) kept Lemos (13-3-1) on the mat for most of the fight.

In the fourth, Lemos had a little success while they were on their feet, landing a right hand that briefly put Zhang on the mat, but Zhang got up and brought Lemos to the mat with a takedown and landed several knees to the head.

"Thank you everybody. Boston, I feel here is my home, the energy you give to me is unbelievable, I feel the energy you gave me," said Weili.

"I've been training every day so hard. I'm not surprised [I won] because I have a great team and all the coaches gave me the technique to win."

On the undercard, Ireland's Ian Garry extended his unbeaten professional record by defeating American Neil Magny with a dominant points victory.

"This breaks me into the UFC top-10, I'm 25 years of age and I'm telling you now, I need to prove myself as the best striker this division has ever seen," said welterweight Garry, who moved to 13 wins.

"And to be the best striker you need to beat the best strikers, and everybody has Stephen Wonderboy Thompson on that list, so give me Thompson whenever, wherever for five rounds.

"I'll prove to you I'm the new generation of strikers in the world."