Arsenal moved seven points clear at the top of the Premier League with an entertaining victory at Brighton.
The visitors were cruising at 3-0 thanks goals by Bukayo Saka, Martin Odegaard and Eddie Nketiah before Kaoru Mitoma pulled one back.
Gabriel Martinelli settled any nerves with Arsenal's fourth before Evan Ferguson added Brighton's second with his first league goal.
Mitoma had a second goal chalked off to deny the home fans a grandstand finish as Arsenal held on for a deserved three points.
Brighton were a long way off the pace for the first hour, but after Martinelli had restored the three-goal advantage they showed great spirit to reduce the arrears again through Ferguson.
They were then convinced they had made it 4-3 with two minutes remaining when Mitoma looked to have scored again, but after a VAR check the Japanese midfielder was revealed to be just offside.
Arsenal are back in action against Newcastle United on Tuesday, buoyed by an increasingly formidable-looking lead over champions City with both sides having played 16 games.
Arsenal stand firm despite defensive wobbles.
Although the Premier League season is still not at the halfway point due to the World Cup hiatus, this win could be a key moment in Arsenal's bid for a first title since 2004.
Brighton had been the last side to beat Arsenal - a 3-1 Carabao Cup win in November - but the prospect of a repeat looked unlikely as soon as Saka had latched on to a rebound from Martinelli's shot to tuck the ball home for his sixth league goal of the season.
The absence of striker Gabriel Jesus through a knee injury collected while on World Cup duty may have worried Arsenal fans, but Saka and Odegaard are compensating for the Brazilian striker's layoff.
Arsenal captain Odegaard's seventh goal of the season came when he capitalised on a poor header out by Billy Gilmour to put his side 2-0 ahead before half-time, the Norwegian's shot going down into the ground and beyond Brighton goalkeeper Robert Sanchez.
And they started the second half just as well as the first, Nketiah poking the ball in from close range after Sanchez fumbled Martinelli's shot from a tight angle.
But they wobbled when full-backs Ben White and Oleksandr Zinchenko were substituted after an hour. Rattled by Mitomo's goal and then a good spell from the hosts, Martinelli finished off a length-of-the-pitch move with a shot that went in off Sanchez's legs to seemingly put the game beyond Brighton's reach.
William Saliba was then too casual on the edge of his own area, allowing Ferguson his chance to pull another goal back, and when Mitoma seemed to have made the score 4-3, Mikel Arteta's side looked worried until the decision by VAR.
Arsenal face a tough January before reaching the league campaign's midpoint, with Tottenham and Manchester United to follow after Newcastle.
Their two meetings with second-placed Manchester City are also yet to come, and Arteta will want to address the defensive frailties that surfaced on the south coast.
Year-end high for Seagulls despite defeat
The Seagulls returned from the World Cup break in fine style, winning 3-1 at Southampton on Boxing Day, but they will regret their slow start here.
Errors by Sanchez played a part in Arsenal's third and fourth goals, but Roberto de Zerbi's side finished strongly after capitalising on a dip in the Gunners' performance following the substitutions of White and Zinchenko.
Ferguson, 18, was a handful on just his third Premier League appearance, all as substitutes, and he was smart enough to latch on to Saliba's error to give his side a sniff of a comeback.
Mitoma was unlucky not get on the scoresheet twice, but the Seagulls nevertheless end 2022 in eighth place - their highest-ever placing in the top flight at the end of a calendar year.
Player of the match
ØdegaardMartin Ødegaard
Brighton & Hove Albion
Squad number22Player nameMitoma
Squad number28Player nameFerguson
Squad number2Player nameLamptey
Squad number30Player nameEstupiñán
Squad number7Player nameMarch
Squad number13Player nameGroß
Squad number5Player nameDunk
Squad number19Player nameSarmiento
Squad number11Player nameTrossard
Squad number20Player nameEnciso
Squad number14Player nameLallana
Squad number6Player nameColwill
Squad number1Player nameSánchez
Squad number27Player nameGilmour
Line-ups
Brighton
Formation 4-2-3-1
1Sánchez
2Lamptey5Dunk6Colwill30Estupiñán
27Gilmour13Groß
7March14Lallana22Mitoma
11Trossard
1Sánchez2Lamptey5Dunk6Colwill30Estupiñán27GilmourBooked at 45mins13Groß7MarchBooked at 57minsSubstituted forEncisoat 76'minutes14LallanaSubstituted forSarmientoat 61'minutesBooked at 81mins22Mitoma11TrossardSubstituted forFergusonat 60'minutesSubstitutes
19Sarmiento20Enciso23Steele28Ferguson29van Hecke34Veltman43Turns49Moran71HinshelwoodArsenal
Formation 4-3-3
1Ramsdale
4White12Saliba6Gabriel35Zinchenko
8Ødegaard5Partey34Xhaka
7Saka14Nketiah11Martinelli
1Ramsdale4WhiteSubstituted forTomiyasuat 60'minutes12Saliba6GabrielBooked at 45mins35ZinchenkoSubstituted forTierneyat 60'minutes8ØdegaardSubstituted forHoldingat 87'minutes5ParteyBooked at 45minsSubstituted forElnenyat 74'minutes34Xhaka7SakaBooked at 54mins14Nketiah11MartinelliSubstitutes
3Tierney16Holding17Cédric Soares18Tomiyasu21Fábio Vieira23Sambi Lokonga25Elneny27Marquinhos30TurnerReferee:Anthony TaylorAttendance:31,647Live Text
Match ends, Brighton and Hove Albion 2, Arsenal 4.
Second Half ends, Brighton and Hove Albion 2, Arsenal 4.
Attempt saved. Evan Ferguson (Brighton and Hove Albion) right footed shot from the centre of the box is saved in the centre of the goal. Assisted by Tariq Lamptey.
Attempt missed. Lewis Dunk (Brighton and Hove Albion) header from the centre of the box is too high. Assisted by Pascal Groß with a cross following a corner.
Corner, Brighton and Hove Albion. Conceded by Rob Holding.
VAR Decision: No Goal Brighton and Hove Albion 2-4 Arsenal.
GOAL OVERTURNED BY VAR: Kaoru Mitoma (Brighton and Hove Albion) scores but the goal is ruled out after a VAR review.
Offside, Brighton and Hove Albion. Evan Ferguson tries a through ball, but Kaoru Mitoma is caught offside.
Kaoru Mitoma (Brighton and Hove Albion) wins a free kick on the left wing.
Foul by Bukayo Saka (Arsenal).
Substitution, Arsenal. Rob Holding replaces Martin Ødegaard.
Corner, Brighton and Hove Albion. Conceded by Granit Xhaka.
Foul by Pascal Groß (Brighton and Hove Albion).
Mohamed Elneny (Arsenal) wins a free kick in the attacking half.
Jeremy Sarmiento (Brighton and Hove Albion) is shown the yellow card.
Jeremy Sarmiento (Brighton and Hove Albion) has gone down, but the referee deems it simulation.
Offside, Brighton and Hove Albion. Pervis Estupiñán tries a through ball, but Kaoru Mitoma is caught offside.
Levi Colwill (Brighton and Hove Albion) wins a free kick in the defensive half.
Foul by Eddie Nketiah (Arsenal).
Goal! Brighton and Hove Albion 2, Arsenal 4. Evan Ferguson (Brighton and Hove Albion) right footed shot from the centre of the box to the centre of the goal.
Our coverage of your Premier League club is bigger and better than ever before - here's everything you need to know to make sure you never miss a moment