Manchester United ended the weekend three points clear of Chelsea with five Premier League games remaining after being held to a 2-2 draw at relegation-threatened Middlesbrough on Sunday.
United led through Cristiano Ronaldo's 27th league goal of the season after 10 minutes but a lively Boro turned things around with two well-taken goals by club record signing Alfonso Alves either side of halftime.
Wayne Rooney equalised for the champions in the 74th minute but, despite a determined late push in unseasonable snowsnorms, they were unable to find a winner.
United have 77 points to the 74 of Chelsea, who won 2-0 at Manchester City on Saturday. Arsenal are third on 71 after drawing 1-1 with fourth-placed Liverpool.