Makeshift striker Mikel Merino scored a crucial equaliser against 10-man Chelsea as leaders Arsenal moved five points clear at the top of the Premier League.

The game's big moment came in the 38th minute, when Chelsea midfielder Moises Caicedo was sent off following a video assistant referee (VAR) review for a late tackle that connected with Merino's shin - his side's sixth red card of the season.

But 10-man Chelsea took the lead shortly after half-time when Trevoh Chalobah's flicked header from a corner looped over David Raya and into the bottom corner.

Arsenal levelled 11 minutes later when Spain international Merino headed in Bukayo Saka's in-swinging cross at the far post.

There were seven yellow cards to add to Caicedo's red in a tense, feisty contest as Chelsea dominated much of the first half, with Estevao Willian having two good chances.

Arsenal were without first-choice centre-backs Gabriel and William Saliba for only the second time since 2021 and their only real effort of the first half fell to Saka, who fired at Robert Sanchez at the near post.

The dismissal was a turning point and it came when VAR John Brooks advised referee Anthony Taylor to upgrade Caicedo's yellow card to red after his studs caught Merino above the ankle - a decision confirmed following a pitchside review.

Chelsea continued to attack, however, after introducing Alejandro Garnacho at half-time, with Reece James first setting up Joao Pedro's close-range header - well saved - before delivering the cross for Chalobah's deft headed goal.

However, Saka got the better of Marc Cucurella - who fouled him four times and was booked - to cross for Merino to equalise at the far post.

Despite being a man down, Chelsea created the best chances to win it through Pedro Neto, substitute Liam Delap and Wesley Fofana.

Merino went closest to an Arsenal winner with an edge-of-the-box strike, while Saka's long-range effort was their only other real threat in the second half.

The draw means Arsenal move five points clear of second-placed Manchester City, while Chelsea are a further point back in third.

The Gunners are now unbeaten in 17 games in in all competitions, stretching back to 30 August.

This match was billed as a battle between superstar midfielders Caicedo and Declan Rice.

Yet Chelsea lost their star man and played 61 minutes without their player of the year from last season, when you include the added time from both halves.

Caicedo has been so integral that he has started all but one Premier League game -last weekend's win at Burnley - since Enzo Maresca took charge 18 months ago.

Given his influence, few expected Chelsea to maintain their high level of performance without him. But that is exactly what happened.

Captain Reece James was sensational as a makeshift midfielder - competing against Rice, who he played with in Chelsea's academy - highlighting his ability to play multiple roles since Maresca came in.

Maresca also kept urging his side to attack, introducing Garnacho and Delap in the second half. It was particularly interesting given Maresca was self-critical about needing to learn about how to play with 10 men amid a spate of red cards in September and October.

Indiscipline remains an issue as Chelsea have received four red cards in 13 league games this season, twice as many as any other team

It is the earliest into a Premier League campaign the Blues have had four players dismissed. They last received more red cards (five) in 2015-16.

On the flip side, Chelsea also showed they can cope without Caicedo, who will now miss Wednesday's trip to Leeds.

Just as it looked as though Arsenal were getting all of their key players back with Viktor Gyokeres back fit and Gabriel Jesus named on the bench for the first time since January - they were dealt a blow with William Saliba ruled out on Sunday through injury.

That meant that Mikel Arteta had to turn to Piero Hincapie and Cristhian Mosquera at centre-back.

Arsenal are usually so dominant from set-pieces but without the towering first-choice pair, they did not pose the same threat.

It was also through a corner that the Gunners went behind, which will disappoint Arteta.

Mosquera looked nervy at times in the heat of a derby and was one of three of the back four, along with Riccardo Calafiori and Hincapie, to pick up a yellow card.

But Arsenal dealt with the period after going behind well, and Merino, like he has done on so many occasions in his short Arsenal career, scored a vital goal to bring them level.

It was not Arsenal's best performance but coming into the busy Christmas period, there will be games when the Gunners just have to find a way to get a result.

Arsenal have navigated a tricky three-game period against Tottenham Hotspur, Bayern Munich and now Chelsea and come out unbeaten.

They are five points clear in top spot and picking up a point against a good Chelsea team, even one down to 10 men, is a good result.

Chelsea face back-to-back away league matches at Leeds on Wednesday and Bournemouth on Saturday. Arsenal host Brentford on Wednesday and have a trip to Aston Villa on Saturday in the Premier League.