Manchester United lost only their second game in 38 Champions League matches at at Old Trafford when they went down 1-0 to Romanian outfit CFR Cluj.
An uninspiring first half lacking in urgency and quality yet chances were created at both ends.
Danny Welbeck had a couple of opportunities, Nick Powell had a shot blocked and in the only flash of quality in the opening 45 minutes Rooney saw a delicate chip palmed away by Mario Felgueiras.
But with Cluj still in with a chance of qualifying for the knock out stage they seemed reluctant to commit men forward despite United's defence still looking unsure at times.
More urgency was shown after the break and it was the Romanian champions who made the breakthrough.
Substitute Paul Scholes gave the ball away in midfield, and with the United defence retreating Luis Alberto hit a stunning 25 yard effort into the top corner to the delight of the travelling Cluj supporters.
United pressed for the remainder of the game but lacked the penetration to force an equaliser and all the while were vulnerable to Cluj on the counter attack, and the game ended with Old Trafford beginning to empty before the final whistle.
A famous victory for the Romanians but results elsewhere mean they will drop down into the Europa League next year.
Referee: Daniele Orsato (ITA)
Venue: Old Trafford
Man Utd scorers:
CFR CLuj scorers: Alberto 56
Yellow cards: Cadu (CLUJ), Scholes (MANU)