LAS VEGAS - Brazil's Alex Pereira pulled off a stunning first-round knockout victory over Jamahal Hill to retain the UFC light heavyweight title while Zhang Weili beat Yan Xiaonan to retain the straweight belt at UFC 300 on Saturday night.

Pereira waved off what looked to be a low blow from Hill before landing a left hook that sent the American sprawling backwards onto the canvas. He then pounced to rain down blows and force the stoppage at the 3:14 mark of the first round.