Everton head to London on Saturday aiming to do something no team has ever managed in the Premier League - to defeat Jose Mourinho at Stamford Bridge.
It's a tall order, no doubt.
However, having sampled victory over the current top-flight leaders at Goodison Park earlier in the season, it's a challenge Roberto Martinez insists his side are more than capable of overcoming.
Ahead of the trip south, we asked Blues legend Graeme Sharp to assess the key battles which could determine where a mouthwatering encounter is either won or lost…
Sharpy says: "These two obviously play well together for England and they seem to be the first choice centre-half partnership. They are very similar; both good defenders who are really quick. Domestically, Jags has done well alongside Sylvain Distin, and Cahill similarly playing with John Terry. When you look at Gary Cahill, a few people were unsure whether he would breakthrough at Chelsea, but he has, and you have to give him great credit for that. It was the same when Phil first came to Everton, because there was doubt whether he would become an established first-team player. He has knuckled down and been really consistent for us and is now the Club captain. His performances this year have been excellent, as they were when he first joined from Sheffield United. You also have to look at how both of these players have developed. When they first came into the Premier League, the emphasis would have been on heading and kicking it clear. Under the managers they are now playing for though, they are probably both playing a different style than that they were used to and they're doing it well.
Sharpy says: "This is another pairing who know each other well from the international scene. Hazard has probably been Chelsea’s best player this season and looks as though he has really settled in under Mourinho’s style of play. We knew he was a good player when he first came to England, but we have seen that he’s added to his game this season. He bagged a hat-trick the other week against Newcastle and is well into double figures already, so he is one that we have to look out for. Kevin Mirallas is something similar; probably not as technical, but quicker and more direct. He’s come to the fore in recent weeks and scored some important goals for us, and seems to be enjoying his football. It’s a good match-up, those two, and they will want to come out on top so when they next meet up for Belgium duty they can give each other a bit of stick.
Sharpy says: "These two do similar jobs for their team. John Obi Mikel is a big strong boy but Gareth Barry has been absolutely phenomenal for us. I can’t speak highly enough of him. The way Roberto plays, with the two holding midfielders, he has been perfect. He has built up a great relationship with James McCarthy and his performances have been excellent. Against Swansea I gave him man of the match because of the way he didn’t waste the ball. He did everything simple, be it with his right or left foot. It will be interesting to see how he matches up against Mikel, who is bigger and a bit physically stronger. A lot of teams were after him when he was a young kid, but he chose Chelsea and has been part of their team under a succession of managers now. Unlike Barry, he’s not necessarily guaranteed a start, because there is so much competition for places at Chelsea. But when he is playing, he is someone that you would call an old-fashioned destroyer; he gets his foot in and breaks things up. If he doesn’t play, there is the chance Nemanja Matic could play. He’s a Mourinho type signing; another big, strong lad. Looking at all the talent on show, we probably have to look at that midfield area and think that whichever team comes out on top there will win the game.
Listen to commentary with Graeme Sharp, live from Stamford Bridge, on evertontv from around 12.40pm.