TORONTO -- Light heavyweight champion Jon Jones survived a challenging first round to choke out former champion Lyoto Machida at 4:26 of the second round in UFC 140 on Saturday night.
The Brazilian didn't tap out and toppled when referee John McCarthy stepped in and the champ finally let go of the standing guillotine choke.
Jones (15-1) became the first 205-pound champion since Chuck Liddell to make consecutive successful title defenses.
"He looked phenomenal. Jon Jones is the real deal," UFC President Dana White said. "I just don't see anybody beating this guy any time soon."
The main event took fight of the night honors, earning Jones and Machida an extra $75,000 apiece.
Machida (17-3) darted in and out and got Jones' attention in the first round with quick attacks and some counters. At one point, Machida drove Jones backward.
It was more of the same in the second. Jones scored with some kicks, but was hurt on the counter.
Jones restored the balance with an elbow that carved open a gash on Machida's forehead. Machida got back up, only to have McCarthy call in the doctor.
The fight was allowed to continue and Jones stunned Machida with a punch, then locked in the standing guillotine choke at the fence.
In the co-main event, former heavyweight champion Frank Mir (16-5) rallied to submit Antonio Rodrigo Nogueira (33-7-1 with one no contest) in the first round.
Earlier, Antonio Rogerio Nogueira -- Rodrigo's twin brother -- pounded out a first-round TKO over former light heavyweight champion Tito Ortiz.