Freire (19-2), who suffered a razor thin split decision to Curran in a title fight earlier this year, required only 79 seconds to put Nunes away in the main event of Bellator 99 at the Pechanga Resort and Casino in Temecula, Calif.
The win sends Freire to this season's featherweight tournament semifinals -- and one step closer to a potential rematch against Curran. Ever since suffering the decision loss in January, Freire says he's lost sleep thinking about the champion.
"He's on my nerves," said Freire, referring to Curran. "If you take my sleep away, I will come after you really hard."
In regards to Freire's latest win, it's hard determining what is more impressive: How quickly he recorded it or whom it came against.
Nunes (18-5) has hit a rough patch as of late, going 2-4 in his last six fights, but has never been finished in a career that includes bouts against dangerous opponents such as Raphael Assuncao, Mike Brown, Kenny Florian and Dennis Siver.
The 30-year-old veteran made an early fatal mistake on Saturday though, when he made an early rush on the circling Freire. "Pitbull" took full advantage of the opportunity, crushing Nunes with a left hook on the ear as he was moving forward.
Referee John McCarthy gave Nunes zero chance to recover, as his body went limp and he fell into a defenseless position immediately from the shot.
Freire will need to repeat the performance throughout the tournament -- and need a little help from Curran for the rematch to happen. Curran is scheduled for his third title defense against Daniel Straus at a Bellator pay-per-view event on Nov. 2.
"I was very trained for this fight," Freire said. "I'm going to run after this belt with all my power."
Guerrerio beats Green; secures place in featherweight semifinals
Guerreiro (18-2) will see the second round of the Bellator featherweight tournament following a closely contested decision victory over Green. All three judges scored the bout for Guerreiro, 29-28.
A former collegiate wrestler, Green (8-2) scored late takedowns in the first and second rounds but would have benefited had he executed them earlier. Each fighter struggled to find consistency on the feet, but it was Guerrerio who made the most of the majority of grappling exchanges.
Green's early attempts to put the Brazilian on his back were thwarted, as Guerrerio showcased strong takedown defense and a technical clinch game. His best work came in the second round, when he got his arms around Green's waist from the back and landed a string of unanswered knees to his opponent's thighs.
Though Green was never in trouble, Guerrerio maintained control and jumped to a two-round lead on the scorecards. Green responded somewhat in the final frame, when he caught a Guerrerio kick and turned it into a takedown. But as was the case in the first two rounds, a 10-9 score when he already down was too little, too late.
The victory improves Guerrerio's Bellator record to 1-1. The 23-year-old prospect fell short in his debut earlier this year, when Magomedrasul Khasbulaev submitted him in the second round. Green suffers the first decision loss of his career.
Matyushenko outlasts Alexander
A light heavyweight contest between two men in their 40s turned out looking like, well, a light heavyweight contest between two men in their 40s.
Vladimir Matyushenko recorded his first victory since April 2011 in a slow, sluggish unanimous decision over Houston Alexander. Judges scored the bout unanimously for Matyushenko by scores of 30-27, 30-27 and 29-28.
The best action took place early, as Alexander (15-10) found a home on several overhand rights and appeared to surprise Matyushenko with a double leg takedown.
Matyushenko (27-7) figured to have a major advantage on the floor heading into the fight though, and after that initial surprise takedown by Alexander, that proved to be the case. He executed a hard throw from the clinch later in the first round, and eventually passed into full mount.
The pace slowed considerably in the second round. Matyushenko landed a few hard left hooks during early exchanges, which, to his credit, Alexander took well. Alexander offered zero offense in the round however, a trend that would continue.
The third round seemed more or less a formality, as Matyushenko scored a takedown 90 seconds in. Alexander would scramble to a turtle position along the fence, where he would remain for the majority of the round.
The loss snaps a two-fight win streak for Alexander. He had finished two opponents prior to this Bellator debut, with both victories occurring this year.
Wilcox scored a come-from-behind submission over Stepanyan
Wilcox advanced to the second round of the Bellator featherweight tournament with a crazy, come-from-behind submission victory over Stepanyan in the second round. Referee Mike Beltran pulled Wilcox off an unconscious Stepanyan at the 2:20 mark.
Wilcox (12-5), who accepted the fight on one week's notice, looked overmatched in the first round. Stepanyan terrorized Wilcox's lead leg with early low kicks, and had him visibly limping at the start of the second frame.
With Stepanyan (13-6) dominating on the feet, Wilcox started looking for takedowns midway through the first round, but failed to get into the hips of the athletic Russian. With every sprawl, Stepanyan's confidence grew. He landed several spinning back kicks to Wilcox's midsection as the round closed.
Wilcox scored his first takedown of the fight shortly after Stepanyan opened a cut on the side of his head with a spinning wheel kick. Wilcox wouldn't do much with top position at first, but eventually took Stepanyan's back on a scramble and locked in a fight-ending rear-naked choke.
Taimanglo oupoints Fisher for a place in semifinals
Taimanglo (19-4-1) managed to outpoint Fisher on the feet despite a significant height and reach disadvantage. All three judges scored it for Taimanglo, by scores of 30-27, 30-27 and 29-28.
Fisher (12-5-1) found some success early countering Taimanglo leg kicks with counter right hands. He refused to take advantage of his length however, eating uppercuts and jabs from the shorter Taimanglo.
The second round appeared to be Taimanglo's best, as he walked Fisher down throughout. Fisher's offensive output dropped significantly from the first round and it was actually Taimanglo who utilized the jab on his longer opponent.
Neither featherweight particularly impressed in the bout, which often times resembled a sparring match more than anything. Nevertheless, it is the 29-year-old Taimanglo who picks up the win, extending his win streak to 10.