Arsenal made a huge statement of their Premier League title intent on Sunday, roaring back from behind to beat in-form Manchester United 3-2 in front of a raucous Emirates crowd.
Eddie Nketiah scored the winner in the 90th minute of a pulsating encounter to spark wild celebrations, as Mikel Arteta's men restored their five-point lead at the top of the table.
Earlier, Nketiah had cancelled out Marcus Rashford's opening goal for United before England forward Bukayo Saka turned the match on its head with a wonderful strike from distance.
The visitors, dangerous on the break, levelled when Argentine defender Lisandro Martinez headed home but ultimately fell just short of extending their long unbeaten run.
"It doesn't get much better than that," Arteta told Sky Sports. "The second half especially, the performance was incredible.
"We were composed and determined at the same time. We never panicked. We always believed that we could win it. We showed the right composure in the box a lot of times but the ball didn't go in. Thankfully at the end it did."
Defending champions Manchester City had earlier Sunday closed the gap to the leaders to just two points with their 3-0 win against Wolves, courtesy of Erling Haaland's fourth hat-trick of the season.
United midfielder Scott McTominay replaced Brazil's Casemiro, who was ineligible after picking up a fifth booking of the season in his side's midweek draw with Crystal Palace, with loan signing Wout Weghorst again leading the line.
New Arsenal arrival Leandro Trossard, who joined late last week from Brighton, had to settle for a place on the bench as Arteta named an unchanged team.
There is growing sense of belief at the Emirates that the Gunners can at last end their long wait for the Premier League title, which they have not won since 2004.
Arsenal flew out of the blocks on a bitterly cold day in London, with Thomas Partey flashing just wide as they surged forward.
But it was United who broke the deadlock in the 17th minute in stunning style, when Bruno Fernandes found Rashford, who skipped past Partey with ease and powered a low drive into the corner of the net from 25 yards.
Arsenal were level just seven minutes later when in-form Nketiah lost Aaron Wan-Bissaka at the back post to nod home Granit Xhaka's cross.
Arteta was booked by referee Anthony Taylor just after the half-hour mark as emotions got the better of him but the first half ended all square after few clear-cut chances.
Arsenal were again first to threaten after the break, pouring forward in search of another goal and they took the lead in the 53rd minute.
Christian Eriksen stood off Saka, who shifted the ball onto his left foot and fired unerringly past David de Gea in the United net from outside the box.
But a pulsating game took another twist when United drew level just six minutes later.
Arsenal goalkeeper Aaron Ramsdale spilled the ball from a United corner and Martinez threw himself at it, looping a header into the net.
Arsenal regrouped and Saka hit the post in a near repeat of his goal as De Gea watched nervously, and the Spaniard made a fine save from Nketiah.
United were close to holding out for the draw but Arsenal took all three points when Nketiah poked home his second of the afternoon after a lengthy VAR check ruled him onside.
The 23-year-old is now top of Arsenal's goalscoring charts this season, with nine goals in all competitions.
Arsenal have 50 points after 19 games, five clear of second-placed City, who have played one game more.
United, fourth in the table, suffered their first defeat in any competition since early November but manager Erik ten Hag was unhappy with the way his team had defended.
"All the goals we conceded today are mistakes, it can't happen," he told the BBC.
He added: "I want to win. It is not good enough, we want to be the number one but make mistakes, that is clear and what I told them."