TORONTO (AP) Jon Jones successfully defended his light heavyweight title, surviving an early scare to submit former champion Vitor Belfort in the fourth round at UFC 152 on Saturday night.

Belfort came close with an armbar in the first round, but Jones' reach, varied attack and ground and pound took a toll on the veteran challenger.

Unable to get his striking game going, Belfort tried to take the fight to the ground where he could use his jiu-jitsu. But he paid a price and finally fell victim to an Americana submission 54 seconds into the round. Jones improved to 17-1, and Belfort dropped to 21-10.

In the co-main event at the Air Canada Centre, Demetrious Johnson won a split decision _ 48-47, 47-48, 49-46 _ over Joseph Benavidez to become the UFC's first flyweight champion.