The precocious 20-year-old Belgian had been linked with a loan move away from Old Trafford but manager Louis van Gaal, who has said he is not for sale, was rewarded after giving the youngster a place in the Premier League side’s starting lineup.
Januzaj, who came in for Ashley Young in the only change to the team that beat Tottenham Hotspur last week, ensured that a second 1-0 victory for United, despite another fairly ordinary performance, gave the 20-times champions a maximum six points.
United were shot-shy against Spurs, with just one effort on target, and this time only produced three as they often struggled to penetrate Villa’s rearguard.
One fine team move, though, was enough to be decisive. Juan Mata slid a delightful probing ball into the box and Januzaj ghosted away from his marker and turned Micah Richards neatly before slotting the ball into the far corner via a deflection.
The Belgium forward’s quality in front of goal was a reminder of the talent that once saw him heralded as the most wanted item in international football before his flame dimmed a little.
Van Gaal, saying he wanted to try Januzaj in his favourite number 10 position, described the goal as “fantastic” and said he was not worried by United’s inability to create opportunities.
“It doesn’t bother me because you only have to score one more than your opponent,” the Dutchman told Sky Sports.
“We don’t give many chances away and every game we have more chances than the opponents. We played better than last week…so I’m very happy.”
Villa, who have not beaten United at home in the league for two decades, created the better chances after halftime only to finish wastefully.
Van Gaal withdrew Januzaj in the second period, introduced Ander Herrera and new signing Bastian Schweinsteiger and the door at the back was locked.
Another United new boy, Memphis Depay, missed a glorious chance when Mata picked him out with another lovely pass.
United had a head start over their title rivals with a rare Friday kickoff after West Midlands Police requested the fixture change because an English Defence League march is planned in nearby Walsall on Saturday.
(Writing by Ian Chadband, editing by Tony Jimenez)