MEXICO CITY -- Fabricio Werdum of Brazil defeated a rusty Cain Velasquez by tap-out in the third round to become the undisputed heavyweight champion at UFC 188 on Saturday night.

With 2:13 left in the third round, Werdum (20-5-1) took down Velasquez, who was coming of a 20-month layoff after suffering injuries in his shoulder and knee. It was Werdum's sixth straight win.

The Brazilian jiujitsu specialist was able to cut local favourite Velasquez (13-2) in the left eye since the first round and the former heavyweight champion struggled through the rest of the fight to overcome it.

Prior to the main event, Mexican-American middleweight Kelvin Gastelum (12-1) got a TKO in the second round to defeat Nate Marquardt (36-15-2), a 36 year-old former strikeout champion.

Gastelum, who missed the welterweight limit in two of his last three fights, was coming off the first loss of his career on January against Tyron Woodley. After Saturday's win, he wants a chance to go back to his former division.

In the lightweight division, Eddie Alvarez defeated Gilbert Melendez by split decision despite fighting with his left eye closed after taking an elbow to the face in the first round.

Also, Tecia Torres remained undefeated (6-0) with a unanimous decision over Angela Hill (2-1) in strawweight. In another fight, up-and-coming Mexican Yair Garcia (6-1) got a split decision victory over Charles Rosa (10-2) in a featherweight combat.

On the undercard, flyweight Henry Cejudo, a 2008 Olympic gold medallist in freestyle wrestling for the U.S., improved to 9-0 with a unanimous decision over Chico Camus (15-6).

"I was very sick the last three days, I suffered from food poisoning and I wanted to cancel but I did my best", Cejudo said. "I won the gold in Beijing, now I want to become a champion at the UFC."

Also, Ireland's Cathan Pendred (17-3-1) won a unanimous decision over Mexico City's Augusto Montano (15-2), Patrick Williams (8-4) defeated local fighter Alejandro Perez (16-6) by submission in the first round, and Efrain Escudero (25-9) took care of Drew Dober (15-3) by tap-out in the first round.