UFC

Jones was doing what has become his ritual before a fight ... he was meditating at a park in Patterson, NJ when he heard a woman scream, "I've been robbed!"

Jones began chasing the man for a good distance. When the fighter caught up with the alleged robber, he knocked the guy's legs out from under him, then placed him in a figure-four leg lock until Paterson cops arrived.

Jones' fight tonight -- UFC 128 -- is in Newark.

Jones tells TMZ, "It was a great pre-fight warm-up for me!"

UPDATE: Jones tweeted about the incident, and even posted a photo (see below) his driver took of the aftermath. He wrote, "I caught him....Coach Jackson finished him ... It feels so good to help others. It gives me power and energy."

27-year-old Huerta -- who was once featured on the cover of Sports Illustrated -- was in front of a bar in Austin around 2 AM on Saturday morning ... when some other people began fighting. Roger was near the scuffle ... when he saw one of the men involved punch a female who was standing near the ruckus.

Once Huerta sees the woman collapse to the ground -- he instantly tries to confront the attacker saying, "You just punched a f**kin' girl."

Moments later, Huerta takes off his shirt ... slams his hat to the ground ... and rushes after the man.

Chaos ensues and people scramble after the fighters, blocking the camera -- but seconds later ... a shirtless Huerta can be seen finishing his attack on the other man ... who is sprawled out on the street.

People rush in to aid the bloody man on the ground -- who eventually gets off the pavement -- as Huerta walks away from the battle ground.

Austin PD tells TMZ that officers were called to the scene -- but so far, no arrests have been made.

We asked the hardcore heavyweight why he would get back in the ring after a mystery illness brought him so close to death a few months ago. His response -- it's the other guy who's risking his life.

Lesnar also offered his thoughts on a new trend making a splash in the world of combat -- fighters drinking their own urine to gain some sort of an edge.

Sources close to Alves tell TMZ Pitbull had an angiogram yesterday morning -- a post-operation procedure that took several hours -- but the results were good.

We're told Alves' doctor is currently sending a letter to the New Jersey Boxing Commission declaring him physically fit to fight. Alves has told us in the past that he wants to get back in the ring ASAP.

Alves was leaving OTM Fight Shop in Redondo Beach yesterday, where he told us he's not only doing well, he's already training again -- just weeks after a surgical procedure to prevent bleeding in his brain.

Operating room spies tell TMZ Thiago Alves just underwent an 8 hour operation to separate an artery from a vein in his brain.

Dana White tells TMZ the operation -- in a New York City hospital -- was a complete success and Pitbull's first words ... "When can I start training again?"

Dana's answer ... a couple of weeks.

We're told Pitbull will be in ICU for the next two days.

TMZ spoke with Alves moments ago, who told us, "I went and saw a specialist this morning who told me I need to have the minor procedure." We're told the procedure will be done in New York.

Alves says he expects to be sidelined from fighting for three weeks -- but expects to be back in the gym in two. We asked Alves if he thought a blow to the head from his recent fight with Georges St-Pierre may have caused his condition and he told us, "I don't think so."

TMZ also spoke with UFC president Dana White who told us, "He'll be back ... it's all good."

Pitbull -- who took this photo moments ago -- is expected to hold a news conference sometime later today at Sazon restaurant in NY.