The Mexican came off the bench at halftime to score two goals and force another as the Red Devils strengthened their grip on top spot with a dramatic victory at Villa Park
Andreas Weimann completed sweeping counterattacking moves either side of halftime to send Paul Lambert's side into a shock two-goal lead.
But Chicharito, who had replaced Ashley Young at the break, made all the difference. The Mexican pulled United back into the game after 58 minutes before another of his shots deflected off Ron Vlaar to level the score.
And the clinical striker finally made United's pressure pay when he headed home Robin van Persie's free-kick in the final minutes at Villa Park.
Sir Alex Ferguson made two changes to the side that beat Arsenal 2-1 the previous weekend. Chris Smalling made his league return in defense in place of Jonny Evans, who had a groin injury, while Tom Cleverley dropped to the bench to be replaced by Paul Scholes in central midfield.
For most of the first half, the possession statistics showed United enjoying around 70 percent of the ball but Villa, led by Vlaar in central defense, continued to stand up to the test and the visitors' frustration grew.
On the stroke of halftime, Lambert's team made its excellent rearguard resistance count. Agbonlahor initiated a break down the left flank that was continued by Benteke. The Belgian showed tremendous pace and power to shake off the challenge of Chris Smalling before rolling the ball into the path of Weimann, who slammed a shot from 18 yards into the roof of the net.
Ferguson did not hesitate to make a change. Young, who had faded as the half wore on, was withdrawn at the break for Chicharito. The sloppy play which had plagued United - for which Scholes was unusually culpable - persisted, though, into the second 45 minutes.
Villa was not as devastatingly quick as it had been for the opening goal, but again it was Benteke that played a significant role in exposing the United defense. His dummy created the space in which Ireland was able to pick out Agbonlahor, whose low cross from the left was swept home by Weimann.
Scholes went some way to making amends by playing the pass that brought United back into the game just before the hour mark. Chicharito did superbly to control the midfielder's chipped ball and shake off Ciaran Clark before steering a low finish through the legs of Guzan.
Within five minutes, United was level. Agbonlahor failed to track the run of Rafael on the right flank and when the Brazilian crossed to the far post, Chicharito was on hand to pounce with the help of a deflection off Vlaar.
Weimann almost had a hat trick when he was denied by De Gea from close range but for the majority of the final 20 minutes, Benteke was the only Villa player not stationed behind the ball. When Robin van Persie struck the crossbar twice in quick succession, the signs were ominous.
And just as Villa seemed to have weathered the worst of the storm, Chicharito headed home from the Dutchman's inswinging free-kick to strengthen the Red Devils' grip on top spot in dramatic style.