Chelsea host Manchester City in this weekend's huge top-of-the-table clash at Stamford Bridge on Saturday – and these two sides have been impressive in the Premier League this season.
With a five-point lead at the top of the Premier League table, Chelsea go into the weekend knowing victory over Manchester City will give them a serious advantage in the title race. It's been a mixed week for the Blues, with Jose Mourinho's men following the shock defeat to Bradford in the FA Cup by securing their place in the Capital One Cup final.
City, meanwhile, have lost their last two games 2-0, first tasting defeat at home to Arsenal in the league before also being knocked out of the FA Cup as Championship Middlesbrough took victory at the Etihad Stadium.
With a tough February to come for both sides, this huge game could prove to be a defining moment in their seasons. There's also the added spice of Mourinho and Pellegrini's fiery relationship plus Frank Lampard's return to Stamford Bridge to heat up a cracking winter fixture.
The Blues are without the injured Cesc Fabregas and the suspended Diego Costa, while Manuel Pellegrini's men are missing Yaya Toure who is still at the Africa Cup of Nations.
It would be a mouth-watering encounter and could potentially decide the league title. The Blues can extend lead at the top of the Premier League to eight points or the Visitors can reduce deficit to just two points with victory at the Bridge.