For Arsenal fans it was the end of a desperate 56-day wait for a Premier League victory; for Chelsea fans the perfect way to ruin a Christmas break.
Frank Lampard’s side would have gone second with a win at the Emirates but instead turned in a poor display in a 3-0 defeat that leaves them outside the top six.
Lampard called out his side for lacking energy and desire, while Mikel Arteta admitted that his Arsenal side “have let the fans down for many weeks.”
So where do they go from here?
‘It doesn’t get any better on Boxing Day’
Arsenal had not won in the Premier League since Pierre-Emerick Aubameyang’s penalty beat Manchester United at the start of November.
The Gunners had only once had a longer run without a win in the Premier League, going eight games winless until Paul Merson secured victory at Maine Road in January 1993.
They had also only won two of the past 17 league meetings against Chelsea but shrugged off all that baggage to open up a 2-0 lead at half-time thanks to goals from Alexandre Lacazette and Granit Xhaka.
“It is a really special day,” said Arteta. “It doesn’t get any better - Boxing Day, playing a London derby at the Emirates and winning the way we’ve done it.
“We were really disappointed and frustrated with the results, not so much with the performances, but the results.
“The players were suffering, our fans were suffering and hopefully this is a turning point and will elevate the confidence of the team because I know that they can play at this level.”
Arsenal had to weather somewhat of a late Chelsea storm - and had Jorginho converted his penalty life could have been interesting for the hosts - but Arteta was full of praise for his team’s spirit.
“From the first whistle you could see the team had the energy and willingness to come out and win the game,” he told BBC Sport.
“The spirit before the game was really positive, they really wanted it. I am pleased for the players and for the supporters - we have let them down for many weeks so it was a good day to give them something to cheer about.”
Arsenal face Brighton, West Brom, Crystal Palace and Newcastle in their next four league matches. Can they sustain this level of performance?
‘We were lazy - I am angry’
Just two weeks ago Chelsea’s 17-game unbeaten run ended at Everton, where a win would have taken them top.
The lacklustre showing at Arsenal made it three defeats in four games and left Lampard repeating his belief that his side are not ready to challenge for the title.
“The teams that win, win, win relentlessly [at the moment] weren’t winning two or three years ago,” he told BBC Sport.
“It takes time and we are not there yet, that’s clear. I felt it when we are on our long unbeaten run and I feel it now. We got a lot wrong today.”
As a team Chelsea covered nearly 4km less than Arsenal, with the hosts having five players (Hector Bellerin, Kieran Tierney, Bukayo Saka, Mohamed Elneny and Granit Xhaka) who ran 10km or more to the visitors’ three (Christian Pulisic, Mason Mount and Ben Chilwell).
Lampard said he had told his players what to expect and felt let down by their approach in the first 45 minutes.
“I am angry because I want us to win games,” he said.
“We were lazy to give away a penalty, lazy to give away a free-kick that Xhaka puts in the top corner and I am very, very disappointed in the way we approached the first half because some things in football are basics.
“It is not tactics or systems, it is do you want to run, back your team-mate out and sprint? Or do you want to jog and say ‘maybe I don’t have to run’, and we took that decision instead of the right one.”
‘They made Chelsea look ordinary’
Former England captain Alan Shearer on Match of the Day
“I said Arsenal could go down and they might have been relegated if Mikel Arteta had continued to play the same team. He made changes and he had to.
“They made Chelsea look ordinary and it was much, much better. The youngsters brought energy to the team. Chelsea were awful, nowhere near good enough. They only came out fighting for the last two or three minutes.
“Chelsea lacked creativity. It wasn’t until the 85th minute they had an effort on target. There was a lack of intensity in the final third. Timo Werner was dragged at half-time.”