Mendes, a late replacement for injured champion Jose Aldo, repeatedly took down McGregor in their main event showdown at UFC 189, and in the second round, dropped vicious elbows that bloodied the Irishman's eyes.
With under a minute to go in the second round, McGregor escaped a submission attempt, got back to his feet, and stuffed another takedown attempt.
With around 20 seconds to go, McGregor took over, landing a series of punches, including a huge left hand to the chin that finally sent the durable Mendes to the canvas.
"Precision with the left hand," McGregor said after the fight. "Nobody can take that left hand. Everyone breaks, and he broke."
Mendes proceeded to cover up, and the referee stopped the fight at the 4:57 mark of the second round to give McGregor a technical knockout victory.
With his win, McGregor is now the interim featherweight champion, and he had some harsh words for the Brazilian Aldo who withdrew from their fight with two weeks to go due to a fractured rib.
"In my opinion, Jose went running," said McGregor. "I had bigger injuries leading up to this fight than that bruised rib, and I still showed up here and performed."
"In my eyes, Jose's gone running. If he wants to come back, he can come back, but I swear to God, his day will come," he added.
Mendes took the fight on two weeks' notice and arguably won the opening round by taking down McGregor and landing flush shots to the Irishman's face. McGregor's longer reach and vicious kicks took its toll on Mendes in the second round, and he responded by again taking the fight to the canvas.
Mendes repeatedly landed elbows from the top position, but once McGregor was able to bring the fight back to the feet, Mendes was unable to fully defend himself from the Irishman's heavy hands.
Mendes, who lost for the third time in his career, was gracious in defeat and thanked McGregor for agreeing to fight him on two weeks' notice.
"He was training for Aldo the entire time, and that's c completely different match-up for him," Mendes said. "The guy's tough… I don't have any regrets."
McGregor improved to 18-2 in his career; Mendes drops to 17-3.
Lawler defends title
In the co-main event, Robbie Lawler successfully defended his UFC welterweight belt by stopping Rory MacDonald in the fifth round of a bloody encounter.
Lawler and MacDonald took turns roughing each other up in the first four rounds, and the result was still up in the air in the fifth.
The champion then took matters in his own hands. He landed a flush shot to MacDonald's bloody nose, and the challenger slowly fell to the mat, only for Lawler to follow up with more punches. The referee stepped it and stopped the fight at the 1:00 mark of the final round.
"That was the accumulation of a beatdown," Lawler said. "It wasn't one punch; it was years of fighting right there, coming to fruition. I'm the champ. I'm here to stay."
Lawler trailed 37-39 on all three of the judges' scorecards at the time of the stoppage, according to UFC.com.
With the win, he improved to 26-10 in his MMA career, while MacDonald lost for the third time against 18 victories.
source: www.abs-cbnnews.com
