Manchester City's challenge for the Premier League title suffered a setback as they were forced to stage a late fightback just to salvage a 3-3 draw against Sunderland on Saturday.
With leaders Manchester United not in action until Monday, Roberto Mancini's side would have returned to the top of the table on goal difference if they had beaten the Black Cats.
But City are now two points behind United and that gap will extend to five if the champions win at Ewood Park.
Emotional outingChelsea kept their top-four bid alive with a 4-2 win over Aston Villa as the home faithful paid tribute to stricken captain Stiliyan Petrov.
Petrov's presence at Villa Park just 24 hours after being diagnosed with acute leukaemia produced an emotional atmosphere.
With reports circulating that the Villa midfielder will retire to focus on his battle, a tearful Petrov was given a rapturous reception from the home fans.
Struggling QPR ended Arsenal's run of seven successive league wins with a shock 2-1 victory at Loftus Road. The third placed Gunners fell behind in the 22nd minute as Adel Taarabt skipped past Thomas Vermaelen to fire in his first Premier League goal.