A lacklustre game at Old Trafford was drifting towards a goalless draw when Mata collected a pass from Oscar and dispatched a low shot that took a slight deflection off Phil Jones on its way into the bottom-right corner.
Mata’s goal means that Chelsea will now go into Wednesday’s crunch clash against Tottenham Hotspur at Stamford Bridge with a three-point lead over their London rivals, who are bidding to crash into the top four.
Arsenal are sandwiched between the pair in fourth, a point behind Chelsea, having played a game more. Meanwhile, Everton remain on course to finish above Liverpool for the second season in a row after holding their city rivals to a 0-0 draw in a scrappy Merseyside derby at Anfield earlier in the day.
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