Midfielder Tom Cleverley struck two goals in the dying seconds to help United overcome Reserve League champions Bolton on Wednesday evening.
The Reds' victory takes them within a point of the top of the table, and extends their unbeaten run to nine games since October's defeat at Blackburn.
The match started in drab fashion - a state which remained unchanged for much of the evening - thanks in no small part to the teeming rain and blustering wind at the largely unprotected County Ground.
The first half was a story of few chances but plenty of endeavour from both sides, with each garnering two bookings. Sean Evans and Corry Evans both gathered questionable cautions for the Reds, while skipper Sam Hewson came closest to opening the scoring with a scorching 25 yard drive which clipped the top of the crossbar.
Hewson was involved at the other end immediately after half-time, hurling himself at Robert Sissons' close-range shot to heroically block an almost certain goal.
Both sides had their first clear chances a minute either side of the hour mark. First Michael Burns drilled a shot wide of Ron-Robert Zieler's near post for Bolton, before Chris Fagan could only steer the ball wide from 10 yards after fine wingplay from Richard Eckersley.
The rain continued to lash down as both sides searched for the all-important first goal. It seemed United's efforts would be in vain, having laboured for almost 89 minutes without finding a breakthrough, until Cleverley struck twice in 65 seconds to snatch the three points.
Firstly, the midfielder smashed home from close range after Eckersley's cross had been only half-cleared by Trotters midfielder Steve Basham.
Then, just over a minute later, goalkeeper Bogdan left his area but fluffed his attempted clearance to the byline. As the ball spun loose some 30 yards from goal, however, Cleverley drilled a superb shot over the stranded goalkeeper and into the untended net.
The result takes United fourth in the table, a point behind leaders Sunderland, and well in the hunt for a third league title in four seasons.
United: Zieler; Eckersley, Lea, Cathcart, Chester; Cleverley, Hewson, C Evans, Bryan; Fagan (Drinkwater 76), S Evans.
Subs not used: Amos, McCormack, James, Norwood.