And the significance goes deeper than the winner likely landing a title shot against lightweight champ Charles Oliveira.
For Poirier, the decision to face McGregor for a third time meant passing up the opportunity to fight for the title vacated by the retirement of Khabib Nurmagomedov. Poirier has held the interim belt before, but being undisputed champ is the dream of every fighter. Poirier is betting on himself, confident he'll beat McGregor again in what should be the most lucrative fight of his career. The plan is to win the money fight first and then go after the title fight. A loss would put his title quest on an uncertain path.
For McGregor, he's trying for his first win over an elite opponent since he beat Eddie Alvarez in 2016. Once considered one of the top pound-for-pound fighters in the world, McGregor now just hopes to silence the critics who suggest he lost his mojo after attaining incredible wealth. Can McGregor regain his championship form? That's a huge part of the backdrop for this blockbuster. And the reality is, despite McGregor's recent plight, he could very well land the title shot with a victory.
For now, it's about the trilogy. McGregor KO'd Poirier in less than two minutes in 2014 as his star ascended to unprecedented heights, and Poirier avenged the loss on Jan. 23 with a second-round KO.
Keep checking back, as this story will be updated with news, features, videos and social media observations as one of the most anticipated trilogies in combat sports history approaches its completion.
One win in nearly five years: What's gone missing for Conor McGregor?
Breaking down McGregor's first win vs. Poirier
On Unlocking Victory, Dominick Cruz breaks down how Conor McGregor set up his knockout win vs. Dustin Poirier in 2014.
Conor McGregor's rise was unlike anything witnessed before in MMA. In his first 10 UFC fights, McGregor went 9-1 with seven knockouts and a UFC-record -- since tied by Justin Gaethje -- nine bonuses. He became the first UFC fighter to hold belts in two weight classes at the same time. Along the way, he became the greatest pay-per-view attraction and ticket-selling draw in UFC history.
On Saturday, McGregor faces a defining point in his career when he and Dustin Poirier complete their trilogy in the main event of UFC 264 in Las Vegas. Since that record-setting start, McGregor is just 1-2 -- his only victory against a past-his-prime Donald "Cowboy" Cerrone -- in nearly five years.
Dustin Poirier, Conor McGregor make weight ahead of UFC 264
LAS VEGAS -- One of the most anticipated trilogy bouts in MMA history is now official.
Dustin Poirier and Conor McGregor both successfully made weight Friday morning at the UFC Apex. Poirier and McGregor both weighed in at 156 pounds. The two men will meet in the main event of UFC 264 on Saturday night at T-Mobile Arena.
Show me the money -- Inside Dustin Poirier's risk in taking the Conor McGregor payday
Cormier details Poirier's KO of McGregor
Daniel Cormier breaks down Dustin Poirier's most effective strikes vs. Conor McGregor in UFC 257. Watch the full episode on ESPN+.
BOCA RATON, Fla. -- It's 2 p.m. on a Wednesday, and Dustin Poirier is methodically wrapping his hands at an empty boxing gym owned by his longtime coach, Dyah Davis. He is 17 days out from his lightweight trilogy fight against Conor McGregor in the main event of UFC 264, and though his mood seems fine, he's tired.
"I haven't had two consecutive days off in nine weeks," he tells Davis, who seems to sympathize but doesn't offer to shorten the session.
Soon enough, a bell on Davis' phone signals Poirier to get to work. "Fine," Poirier says. "I'll take a break when I knock this motherf---er out."
Best bets for UFC 264: Conor McGregor vs. Dustin Poirier 3
With odds that have floated for months, the market still hasn't really taken a significant side in this one. McGregor's odds have historically seemed inflated due to his popularity, and in this space nearly six months ago, we took the underdog value on Poirier. Now, with the benefit of having seen them fight for seven and half minutes, the once long odds on Poirier have drawn close to even. With such affordable odds, we're left with a simple question: Who has the better chance to win?
Wagenheim: McGregor talked his way to the top of the UFC, but has he lost his edge?
As Poirier and McGregor prepare to complete their trilogy on Saturday at UFC 264 in Las Vegas, the question lingers about whether McGregor still has it in him to defeat an opponent before the first punch is thrown. There has been a bit of acrimony flung back and forth this time around, but it was initiated by Poirier, who chided McGregor for not having followed through on a pledge to donate to Poirier's charity.
McGregor responded with vitriol and with a donation -- to a different charity in Poirier's hometown.
Then, on Tuesday, McGregor posted a voice message with a couple of insults and said he was coming for Poirier. He later tweeted what appeared to be a direct message request from Poirier's wife, Jolie. There were no accompanying words from McGregor, just insinuation. Dragging family into the trash talk is a low blow, and both that and the voice message seem more like acts of a desperate man than masterful head games. But we'll see on Saturday.
Chris Weidman's keys -- and prediction -- for the trilogy
Former middleweight champion Chris Weidman analzyed the first two McGregor-Poirier bouts for ESPN in order to identify the keys to Saturday's trilogy main event.
From McGregor's stance to his confidence, Weidman sees areas the former champion can improve on to change the outcome.
Weidman also predicts whether he thinks McGregor can do it.
No title at stake, but McGregor's legacy will be on the line
Let me tell you why there is so much riding on this trilogy fight -- it's not outlandish to say that the entire narrative of McGregor's athletic career could be on the line.
As of this moment, what would we say about McGregor the fighter? Not the superstar. Not the entertainer. If he were to retire right now, how would we define his athletic achievement?
-- Brett Okamoto
Real or Not: Poirier won't regret decision, win or lose
If Poirier loses Saturday, he falls back into a pack of elite contenders at lightweight. He would likely need at least one more win to get another title shot.
If that were to happen, would he regret his choice not to fight for the belt first and then hope he could finish the lucrative trilogy against McGregor?
Could McGregor put title shot on hold if he beats Poirier?
Will McGregor decide the time is finally right to revisit the Nate Diaz trilogy? He'd be playing with house money at that point, and I don't see why the UFC wouldn't get on board with it. What I mean is: Win or lose against Diaz, he could still fight for the 155-pound title next.
Real or Not: Wonderboy, Sean O'Malley primed for big moves; Greg Hardy has peaked
Our panel takes a look at at the other fights on a loaded main card, including:
Is a top-15 heavyweight ranking the ceiling for Greg Hardy?
Capacity crowd in Vegas will be on hand
A capacity crowd will be present at UFC 264 in Las Vegas, UFC president Dana White announced. The pay-per-view will be held at T-Mobile Arena.
"I'm so happy to finally be able to say Vegas is back," White said in his tweeted video. "This summer Las Vegas is back open for business, and on July 10, UFC 264 will be at the T-Mobile Arena in Las Vegas at 100% capacity. Ladies and gentlemen, that's 20,000 fans."
The charity saga: McGregor donates, but not to Poirier
Conor McGregor donated $500,000 to a Boys & Girls Club in Louisiana as an apparent resolution to an issue he had with rival Dustin Poirier.
In April, McGregor and Poirier bickered on social media about McGregor's pledge to donate $500,000 to Poirier's The Good Fight Foundation. Poirier tweeted that McGregor reneged on his promise following Poirier's TKO win over McGregor at UFC 257 on Jan. 24. McGregor shot back that his team wanted more details about what the money would be used for.
Sept. 27, 2014: The first time they fought
Conor McGregor (16-2) made quick work of another UFC featherweight, knocking out Dustin Poirier with a grazing left hand at 1:46 of the first round.
There was some controversy over whether McGregor hit Poirier (16-4) in the back of the head with his elbow as he followed through, but referee Herb Dean made no such signal, and Bob Bennett, Nevada State Athletic Commission executive director, told ESPN.com the elbow landed to a legal area of Poirier's head.
"He caught me with one, but other than that I feel good. I'll have to go watch it back, but it felt great," McGregor said.
"I'm honored to hear a percentage of the tickets were bought in Ireland and my countrymen came to support me. When one of us go to war, we all go to war. Our countrymen have been fighting our whole lives. This is where we come from."
-- Brett Okamoto
Jan. 23, 2021: The rematch: Poirier stuns McGregor
Dustin Poirier avenged his loss to Conor McGregor and picked up by far the biggest win of his career.
The perennial UFC lightweight contender shocked McGregor, beating him via TKO after swarming him with punches at 2:32 of the second round Saturday night in the main event of UFC 257 in Abu Dhabi, United Arab Emirates.
-- Marc Raimondi
How Poirier grew after losing to McGregor and his head games
The only time Dustin Poirier wanted to fight an opponent outside of the cage was the week of UFC 178.
Poirier remembers standing behind a curtain at the MGM Grand Conference Center in Las Vegas in September 2014, waiting to get on the scale. He recalls seeing a few scuffles in the crowd, which was packed with Irish fans. He remembers being dehydrated and anxious to weigh in. And he remembers tension after weeks of being the target of Conor McGregor's trash talk.
"I wanted to make the guy pay, you know? I was angry," Poirier says. "I remember wanting to fight him at the weigh-in, which is crazy to look back at. I was just in such a weird place in my mind."
-- Brett Okamoto
McGregor's journey: Success, controversy, star power
UFC president Dana White remembers the first time he heard the name Conor McGregor, a name that would forever change the promotion.
White was in Dublin to receive an award from Trinity College in 2013 when he invited UFC fans on Twitter to join him at a nearby pub after the ceremony. Drinks would be covered by the UFC president.
It was that night, Feb. 11, when he first heard a name that would become the most talked about in UFC history.
"The place was packed, full of people," White said. "I was in there with the fans all night, and everybody kept talking about Conor McGregor."
See which of the two is ranked among ESPN's P4P top 10
There was a time when Conor McGregor was considered one of the best fighters on the planet, with a future that could make him the GOAT.
But a lucrative sidetrack to box Floyd Mayweather Jr. derailed those plans on Aug. 26, 2017. Was it a temporary derailment? The answer might be revealed at UFC 264.
Meanwhile, Poirier has been busy and successful, beating some of the best in the world, including McGregor in the rematch.
One of these two was ranked among the top 10 pound-for-pound fighters in the world.
What they're saying
Conor McGregor has the be the wealthiest man that still wants to get into a real bloody fight. I gotta respect that 💯— Terrance McKinney (@twrecks155) June 30, 2021
3 fights against me for any man is an early grave. God bless 🙏— Conor McGregor (@TheNotoriousMMA) July 2, 2021