Sean O’Malley shocks the world with stunning second round knockout of Aljamain Sterling to win the bantamweight title at UFC 292

Sean O’Malley won the UFC bantamweight title on Saturday night, stopping Aljamain Sterling in the second round in the main event of UFC 292 at the TD Garden.

O’Malley (17-1), of Phoenix, dropped Sterling with an overhand right early in the second. With Sterling on the mat, O’Malley hammered the defending champion to the head with his left hand until referee Marc Goddard stopped the fight 51 seconds into the round.

The 28-year-old O’Malley fought for the first time in a five-round bout. The 34-year-old Sterling fell to 23-4. He entered the fight with 10 straight victories.

The first round went fairly smoothly. Sterling attempted a takedown with 30 seconds left, pinning O’Malley against the fence before the round ended.

Sterling, of Uniondale, New York, was on his fourth defense of his bantamweight title.

In the co-main event, Zhang Weili of China retained her strawweight title with a 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 minor success while they were on their feet, landing a right hand that momentarily put Zhang on the mat, but Zhang got up and brought Lemos to the mat with a takedown, landing several knees to the head.