McGregor, 32, will be chasing his first victory since January 2020 while the 31-year-old Poirier (27 wins, five defeats) will be looking for a third consecutive victory.
Ngannou stopped Stipe Miocic with ferocious punches early in the second round to claim the heavyweight title at UFC 260.
UFC 259: Jan Blachowicz ends Israel Adesanya's undefeated run; Amanda Nunes overpowers Megan Anderson
It was the first defeat inflicted on the 31-year-old Adesanya, who was stepping up in weight, in his 21-fight career.
The 32-year-old McGregor had been an overwhelming favourite to register a winning return after a year away from the octagon.
Poirier, who now has a UFC record of 27-6, used low calf kicks in an effort to put McGregor (22-5) off his usual ferocious stand-up game — and it worked
Conor McGregor vs Dustin Poirier 2 preview and prediction: Plucky Irishman to pick apart American in short order
The blueprints to defeat McGregor exist. Like Nate Diaz, you have to be insanely durable, take his best shot and keep coming forward Terminator-like.
McGregor (22-4) was last seen demolishing American welterweight Donald Cerrone (36-15) via a knockout in just 40 seconds at UFC 246 in Las Vegas last January
Figueiredo (20-1) earned his record-tying seventh stoppage victory in the 125-pound division by clamping onto Perez's neck out of a scramble at 1:57 in the opening round.
A frustrated McGregor, who had previously announced multiple retirements before returning to the octagon, said in July he had retired.
Nurmagomedov has not only paved the way for future Dagestani-Russian athletes in Mixed Martial Arts, but has also shown that a fighter with an uncompromising work ethic and a measured and respectful persona can make it to the top of the mountain in an age of showmanship.
UFC 254: Khabib Nurmagomedov announces retirement from mixed martial arts after choking out Justin Gaethje
Nurmagomedov (29-0) made the announcement immediately after he impressively finished his first fight since the death of his father and lifelong coach Abdulmanap Nurmagomedov in July.
If Nurmagomedov, the undefeated UFC lightweight champion, can get Gaethje on the ground and keep him there, ‘The Eagle’ should get his hand raised at the end of the night.
As Jon Jones-Israel Adesanya trash talk threatens to devolve into unseemly spectacle, UFC misses danger signs yet again
Personalities sell. Rivalries sell. Trash talk sells. It also helps if you can fight well. Here's a look at the endless trash-talk culture that has associated itself with boxing and MMA.
Pacquiao vs McGregor may result in plenty of dollars for UFC star, but risk far outweighs the reward
The upcoming bout between Filipino legend Manny Pacquiao and Conor McGregor is likely to be different from the MMA star's foray with Floyd Mayweather Jr. It is because while Mayweather did not knock McGregor out senseless, Pacquiao can do precisely that.
Conor McGregor released without charges after being taken into custody in Corsica for alleged sexual assault, indecent exposure
Conor McGregor, no stranger to controversy, was taken into police custody on suspicion of attempted sexual assault and indecent exposure, was released on Saturday without being charged, his lawyer said.
Jones has won a UFC-record 14 title fights, and he hasn't lost any fight since 2009 — but thanks to two doping violations, he has fought only six times since January 2015.
Khabib Nurmagomedov (28-0) holds the longest active unbeaten streak in MMA, and he became the UFC's lightweight champion in April 2018 by defeating Al Iaquinta for the vacant belt.
Fight Island will host four UFC events in 14 days, starting with three championship fights at UFC 251 this weekend.
UFC 251: President Dana White reveals mixed martial arts event will be hosted at Abu Dhabi's 'Fight Island'
White had said in April that the UFC was close to securing a private island to stage bouts for international fighters unable to enter the United States due to travel restrictions amid the COVID-19 pandemic.
UFC President Dana White has already said McGregor is next in line for a title shot at the winner of lightweight champion Khabib Nurmagomedov's bout with Justin Gaethje this summer.