LAS VEGAS -- The UFC welterweight title came ever so close to booking a return flight to Canada on Saturday night.
Robbie Lawler simply refused to let it happen.
Lawler (26-10) defended his 170-pound belt for the first time in the co-main event of UFC 189, knocking out Canadian challenger Rory MacDonald at the 1:00 mark of the fifth round at the MGM Grand Garden Arena. In the other main event, Conor McGregor defeated Chad Mendes by second-round knockout.
Fighting out of Tristar Gym in Montreal -- home to longtime welterweight champion Georges St-Pierre -- MacDonald (18-3) gave Lawler all he could handle in the five-round fight, but eventually succumbed to a straight left hand. The punch didn't knock down MacDonald, but it appeared to injure him in some way. After a short delay, MacDonald crumpled backward, prompting referee John McCarthy to step in.
"That was the accumulation of a beatdown -- that wasn't one punch," Lawler said. "That was years of fighting. I'm the champ and I'm here to stay."
MacDonald, 25, was attempting to become the first UFC champion out of Canada since St-Pierre vacated the welterweight title in late 2013.
At various stages of the bout, it appeared MacDonald was on his way to doing so.
Both men fought at a measured pace in the opening round, targeting one another with jabs and low kicks. MacDonald attempted his first takedown of the fight 3:30 into the round, but it was easily stuffed by Lawler. MacDonald attempted several takedowns later in the fight, none of which were successful.
Action picked up in the second round, and it was Lawler who started to find his groove. He formed a small welt under MacDonald's left eye with his jab and hurt him with 90 seconds remaining in the round with a straight left.
Just when it appeared as though MacDonald might fold under Lawler's offense, he started to respond with punches and kicks in the pocket. With one minute left in the third round, MacDonald elevated a right head kick that got through Lawler's defense. Lawler tried to hide the effects of the shot, but his legs shook and MacDonald smelled blood. He followed Lawler to the fence and unloaded elbows and knees until the bell ended the round.
Spewing blood with every breath, the two continued to meet in the middle of the Octagon in the fourth round. MacDonald opened a nasty looking cut on the corner of Lawler's mouth and went to the well with the right head kick that had hurt him in the previous round. A look of concern drew across the 33-year-old Lawler's face, but he continued to fire away with left hands and sprawled on two key takedown attempts by MacDonald.
"I showed everyone I'm a true fighter and I come to fight no matter what," Lawler said. "I keep coming and I come to knock people out. My coaches told me to stay basic, pick him apart, and I would eventually knock him out."
Lawler's coaches' words proved prophetic, as MacDonald finally went down in the fifth round. Lawler was down 39-37 on all three judges' scorecards entering the round, meaning he essentially had to have a knockout to win.
The result was somewhat similar to a previous three-round fight between the two. In a split-decision win in November 2013, Lawler overcame a bad second round to knock MacDonald down in the third and take over the end of the fight.
It is only the second time MacDonald has been finished.
After the fight, MacDonald's trainer, Firas Zahabi, posted a photo to Instagram of Lawler visiting with MacDonald as he received treatment.