Former Arsenal defender William Gallas has said that the fans' reaction to him after signing left him shocked and surprised.
Gallas, who was a bargaining chip as part of Ashley Cole's highly controversial move to Stamford Bridge in 2006, was taken aback by how well he was treated, having signed from their rivals.
In an interview with FourFourTwo, the former France international stated that his first appearance in an Arsenal red left a lasting impression on him.
"I would say that my best memory at Arsenal is actually my first game against Middlesbrough," he claimed.
"Because I’d arrived from Chelsea, the supporters would normally boo you.
"But when I was out on the pitch during the warm-up, they all applauded me. That was really nice – I did not expect that."
Gallas' relationship with the Gunners' faithful did sour though, as he moved on to arch-rivals Tottenham Hotspur, though he'd be the first to admit he didn't expect a warm welcome after that.
The rivalry between Chelsea and Arsenal has died down over the years though, with the latter becoming less used to success. Aside from the FA Cup, Arsenal haven't won a major trophy since the 'Invincibles' won the Premier League in 2004.
Chelsea on the other hand, have picked up 11 major trophies since Gallas made the move across London, including the Champions League and three league titles.
However, all is not rosy at Stamford Bridge, with rumours growing throughout the summer regarding manager Antonio Conte's discontent at their transfer dealings.
This will only have been exacerbated by their failure to land the Italian's midfield targets towards the end of the window - notably Alex Oxlade-Chamberlain, who turned down a money-spinning contract, instead signing for Liverpool.
Ross Barkley was also set to sign for the Blues, but had a change of heart after reportedly undergoing a medical, despite the Liverpudlian disputing those claims, though he is said to prefer a move to Spurs.
Chelsea have made a positive start to the season though, with victories over Spurs and Everton, after a shock opening day loss to Burnley, albeit with nine men.
Arsenal, though, appear to be in disarray.
They've conceded the second-most goals in the league with eight, and have suffered back-to-back losses away at Stoke and Liverpool, the latter a humiliating 4-0 battering.
Oxlade-Chamberlain turned down a lucrative new contract before leaving, while the Gunners look set to lose star man Alexis Sanchez on a free next year when his contract expires.
The decision to hand Arsene Wenger a new contract after their victory over Chelsea in the FA Cup final appears to have been a rather hasty one with hindsight.