"Some managers, when they leave clubs, they like to wash their dirty clothes, which means they'd speak about what happened. They go back and speak and speak and speak.” Jose Mourinho refused to speak ill of his former club ahead of Manchester United's trip to the Stamford Bridge on Sunday. The Portuguese might be taking to the pitch with mixed feelings, but the North London crowd will show no mercy on his side. They will taunt the United players with their chants, they will go after the referee if any decision goes against their team and will not even hesitate to boo their beloved “Jose” if things go south. But such has been the rivalry between United and Chelsea over the last ten years. Here are the top five clashes that have defined the clashes between the English giants.

This was one of the classic encounters that signified the domestic struggle for supremacy between the two clubs. Sir Alex Ferguson's men reclaimed the Premier League title from Chelsea after the blues' back-to-back wins in 2005, 2006 and were close to wrapping up a second league title in a row. United travelled to Stamford Bridge hopeful of winning the tie to wrap up the league and they had ample reasons for it.

But it was Sir Alex who had the last laugh, as United not only claimed the Premier League staying two points clear of Chelsea, but also denied the Blues their Champions League title in a thrilling penalty shoot-out in Moscow. It was more agonizing for Chelsea since their season both started and ended with a defeat to the Red Devils on penalties. Remember John Terry's slip? It was that season.

This was a Cristiano Ronaldo special! The match underlined his growing stature as United's new superstar. United were unstoppable following their double win in the previous season, and their star was at the peak of his powers. Things started heating up when United got a corner just before the interval and Rooney intentionally rolled the ball out of the corner quadrant. Ryan Giggs, who was aware of this, crossed the ball from which Ronaldo headed home. But referee Howard Webb said, “No Goal” sparking some wild protests from the obviously guilty United players.

Ronaldo was then unfairly denied a goal for offside when he finished cleanly from Rooney's through ball. The referees and Chelsea could do nothing to take the sheen off Ronaldo's performance though. The Portuguese's free-kick in the final half hour found Dimitar Berbatov in the box, who headed it past a hapless Petr Cech to seal the win for the hosts. United completed a hat-trick of league titles, with Ronaldo top scoring with 18 league goals and also winning the FIFA's World Player of the Year.

Roman Abramovich got rid of Luis Felipe Scolari as Carlo Ancelotti took over the reins at Chelsea in the summer of 2009. Chelsea were back in the title race after three years and were level on points with Manchester United as they travelled to Old Trafford for a title showdown. United were never prolific during the 2009-10 season after losing Cristiano Ronaldo to Real Madrid in the summer, but grinding out results kept them in the fight.

Losing Wayne Rooney to an injury forced Alex Ferguson to field Darren Fletcher and Antonio Valencia in the midfield. Things went wrong for the home side when Veteran striker Joe Cole gave Chelsea the lead on 20 minutes with a clever back-heeled finish. Ferguson was left fuming on the touchline as United were denied two penalties by referee Mike Dean giving the impression of the title slipping away from United.

Chelsea legend Didier Drogba then sealed the game and put Chelsea two points ahead in the first position after he came off the bench to score the second goal for Chelsea. Substitute Federico Macheda pulled a goal back for United but it was not enough to prevent the defeat. Despite winning the league in May 2010, Ancelotti would soon become the third manager in as many years to be sacked at Chelsea.

Chelsea 3-3 Manchester United (5th February 2012)

The match referee Howard Webb, who was assigned to calm the tensions on the pitch, only sparked outrage in the away stand when he waved off Ashley Young and Danny Welbeck's penalty claims in the first half. The hosts took the lead through Jonny Evans' unfortunate own goal and Juan Mata doubled the lead with a sensational volley. This prompted Chelsea fans to taunt Rio Ferdinand by chanting “There is only one England captain!” referring to their captain John Terry. They were successful to an extent when David Luiz's header got a deflection off Rio Ferdinand and into the net.

Chelsea 2-3 Manchester United (28th October 2012)

Chelsea were leading the points table going 8 league matches undefeated. But it was Ferguson's men who were ahead in the 4th minute when Van Persie's shot hit the post, cannoned off David Luiz and bundled into the goal. The striker doubled United's lead eight minutes later with a sublime right-footed finish from Antonio Valencia's low cross. Chelsea once again fought back through Juan Mata, when Ramirez rose high to head the Spaniard's free-kick home. 

When things were heading towards a dull draw, referee Mark Clattenburg stirred back the old memories when he red carded Branislav Ivanovic in the 63rd minute for a foul on Ashley Young. There was an uproar in the stadium when Clattenburg booked Fernando Torres after believing that the Spaniard had dived over Jonny Evans' tackle. This removed the sting out of Chelsea's attack, but poor refereeing continued when the linesman failed to raise the flag against Javier Hernandez's 75th-minute winner for United. United never looked back after that game and went on to win the league for the 20th time in the history and 13 under the Sir Alex Ferguson.