Chelsea's lead in the English Premier League was limited to just two points when they were held 1-1 at Hull City on Tuesday.
Defender Steven Mouyokolo gave Hull a surprise lead in the 30th minute and Didier Drogba scored in his 20th goal to equalize 12 minutes later.
The draw kept Chelsea on top of the 20-team standings with 55 points, two points clear of defending champions Manchester United. Arsenal were third with 49.
Hull were still in the relegation zone but levelled on 21 points with the three teams immediately above it.
Also on Tuesday, Premier League strugglers Wolverhampton Wanderers and Wigan were knocked out of the FA Cup after losing fourth-round replays to lower-league sides.
Crystal Palace defender Danny Butterfield scored a hat trick in seven second-half minutes to give the League Championship side a 3-1 win over Wolves, while Wigan were humiliated 2-0 by visiting Notts County of the fourth tier.