Rory MacDonald's fortitude was already well known from his epic 2015 welterweight title loss to then-UFC champion Robbie Lawler.
Saturday at the Forum, MacDonald burnished his reputation by overcoming a gruesome, third-round left leg injury to wrest the Bellator MMA welterweight belt from Douglas Lima by unanimous-decision scores of 48-47, 49-45, 49-46.
"He's the best fighter I've ever fought. Easy," MacDonald said after surviving a kick that would have finished lesser men.
Lima (29-7), after landing hard first-round jabs on the nose MacDonald broke in his loss to Lawler, delivered his massive kick to MacDonald's left leg in the final minute of the third round.
MacDonald initially tried to rise, but the pain made that both impossible and unwise, so he opted to survive by getting on top of Lima and punching the challenger.
MacDonald limped heavily back to his stool at the bell, the damage leaving a grotesque lump in his leg that would force him to be carried to his dressing room after the fight.
Looking at the leg afterward, MacDonald joked, "I think I have a person growing inside me."
Lima took down MacDonald (20-4) to start the fourth, then kicked the wounded leg again, but MacDonald managed to find his way atop Lima to close the round.
After keeping ice on the leg throughout the break, MacDonald got on top of Lima again and delivered so many elbows to his forehead that the Brazilian bled heavily above his right eye.
"I came here with my very best and this guy gave me a challenge," MacDonald said.
The victory, accomplished with UFC welterweight Nate Diaz watching, gives MacDonald a claim as MMA's top 170-pounder since he has defeated both Diaz and current UFC welterweight champion Tyron Woodley.
In the main event, Chael Sonnen edged former UFC light-heavyweight champion Quinton "Rampage" Jackson 29-28 on all three scorecards to win the opening fight in Bellator's eight-fighter heavyweight tournament, advancing to face the winner of Fedor Emelianenko-Frank Mir later this year.
Sonnen scored three takedowns of Jackson in a fight that was otherwise lacking in compelling action.
In his first bout since losing his belt in June, former lightweight champion Michael Chandler shrugged off some early punches to the face by Goiti Yamauchi to fiercely land more damaging power punches and proceed to victory by unanimous decision.
Judges awarded Chandler victory by scores of 30-26, 30-26, 30-25.
Chandler (17-4) closed impressively, knocking Yamauchi down in the third round and surging atop him to deliver a battering of punches to the head to clinch the one-sided decision over a fighter hyped as one of Bellator's most dangerous.
"I don't want to say I proved everybody wrong, but I proved them wrong," Chandler said. "Everybody said he's the toughest guy in the world …"
Chandler will be pointed to a rematch with champion Brent Primus, Bellator President Scott Coker said.
"I'm a model employee," Chandler cracked. "I do what I'm told."
The Forum card featured several Southland fighters beyond Irvine's Jackson.
Whittier featherweight Aaron Pico (2-1) showed that his placement on the televised card was well deserved, blasting Shane Kruchten with a hard left hook to the belly that floored him and set up Pico for a first-round finish just 37 seconds in.
Pico, who simultaneously trains under the guidance of MMA veteran Antonio McKee and seven-time boxing trainer of the year Freddie Roach, lost his pro debut in June, but he's looked sensational since, fulfilling his stature as perhaps the sport's brightest prospect.
He dropped Kruchten with a combination of body punches before the defining blow.
"I just need to relax and do what I do," Pico said. "I'm not here to talk. I'm a professional. Put them in front of me. I do my talking with my fists."