Jose Mourinho quickly dispelled some pre-match Manchester United feud rumors after his first win as Chelsea manager.
Mourinho united the blues in June 2004 after winning the Champions League with Porto and became known as 'The Special One' thanks to his iconic first press conference.
Chelsea backed the appointment with an investment of around £136m in signings a year after Roman Abramovich took over.
Didier Drogba, Petr Cech and Ricardo Carvalho were just three of the big names to arrive at Stamford Bridge ahead of the 2004/05 season.
However, the then-United Defender Mikael Silvestre questioned the spirit of the Chelsea team in the days before the clash between the two teams.
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“Even if you buy top-level international players, you need spirit in the locker room,” he said. sky sports.
“You don't get that in a month, even if you live and work together 24 hours a day, seven days a week.”
However, Chelsea put this feeling aside and took a 1-0 home victory thanks to Eidur Gudjohnsen's goal after 15 minutes.
Mourinho therefore had a dream start with Les Bleus and then had no qualms about declaring Silvestre's words incorrect.
“When Silvestre said we didn't have time to create a great team spirit, he was wrong,” he said, according to the guardian.
“Today we were a team mentally and we had to win this game because of the three points we got against our direct rival.
“And I think we deserved it because of the team spirit.”
The victory sparked Chelsea's campaign to win the Premier League title in which they lost just once and conceded just 15 goals, a record that still stands today.
The Blues also won the first leg against United 3-1 at Old Trafford and finished 18 points clear of them at the top of the table.
Chelsea's league title, their first in 50 years, accompanied their League Cup win to help kick-start a hugely successful relationship with Mourinho.
They retained their Premier League crown the following season before winning another League Cup and FA Cup in 2007.
Mourinho left at the beginning of the 2007/08 campaign, but returned in 2013 for a second spell after spells at Inter Milan and Real Madrid.
Chelsea won their third Premier League title under him in 2015, as well as another League Cup, before leaving again later that year.
He returned to management in 2016 at United, which host Chelsea on Sunday just two days after they announced the slope arrival of Rubén Amorim as their new head coach.
Red Devils fans will be hoping the highly-rated Portuguese coach will follow in his compatriot's footsteps and make an equally quick impact on his new team.