Manchester City won't want their opponents opening up an eight point lead over them come Sunday evening.
The defending champions - after their two impressive wins against Newcastle United and Liverpool - have been stuttering somewhat. A home loss to Stoke City, a draw away to Arsenal - though a respectable result - and a late defeat to Bayern Munich in the Champions League. Three games, no wins, and the only side to have beaten them in the Premier League at the Etihad Stadium last season next up for them.
Chelsea are that side - and in Jose Mourinho's first spell at the club, his two title triumphs consisted of his side starting quickly, putting a substantial run of wins together at the start of the season with at least one victory against a team of significant prowess along the way.
Chelsea have won four from four and sit five points clear of City going into the game. A win for Jose Mourinho's side would take them eight points clear of the defending champions at such an early stage of the season. It'd be too early to say it's commanding but it would be significant if the Blues manage to get the bit between their teeth.
Their biggest test so far this season, on paper at least, has been the trip to Everton and they managed to win 6-3. City will have faced the rest of last season's Premier League top four before the end of September.
A win against Chelsea for the home side could put them in a great early season position. They'd be two points behind their opponents at the end of the game in the knowledge that they have faced three of their most difficult fixtures this season.
Inevitably, if it's a tight title race come the end of the season, the record against the top sides will be dug out by various media outlets. A huge game, and even with the season still at the stage where the league table looks unfamiliar, it could be huge in the context of this season's title race.