United made heavy weather of it, but procured three more precious points against Derby County after Cristiano Ronaldo struck a late winner at Pride Park.
Paul Jewell's rock-bottom Rams frustrated the Reds all afternoon as a string of chances went begging, before Ronaldo was on hand with 14 minutes remaining to stab home from close range.
The winger's intervention spared United the embarrassment of dropping points against a side with just one league win to their name all season and, but for two fine saves from debutant Ben Foster, the hosts could even have snatched all three points.
An afternoon of frustration looked far from likely in the early stages as United dominated. Ryan Giggs, making his first appearance in four matches, almost scored within seconds of kick-off as he rose above the home defence, but Rams keeper Roy Carroll managed to plunge to his left and grasp the ball just in front of his line.
The former United goalkeeper was helpless two minutes later as Evra slid Ronaldo on the left side of the area, only for the winger to lash his left-footed effort off target. Ronaldo's mood was not helped by the attentions of Darren Moore, who earned the first yellow card after six minutes for raking his studs down the Portuguese star's left leg.
Derby conceding a string of corners as they clung anxiously to parity. The hosts had the woodwork to thank after 10 minutes when Ronaldo's low shot curled onto Carroll's right-hand post, while Anderson came within close moments later with a drilled effort.
Giggs then had another chance after 20 minutes but, having half-rounded Carroll, the veteran winger could only skew his shot wide under the attentions of Dean Leacock.
The Reds' pressure was incessant, and more really should have come of a break after half an