Wayne Rooney's first goal of the season fired Manchester United to victory against Roma at Old Trafford.
Rooney gave Curci no chance with a sweetly-struck winner
There was to be no repeat of the 7-1 drubbing handed out to Roma in April by United in last season's quarter-final.
Chances were at a premium with Cristiano Ronaldo and Francesco Totti restricted to long-range efforts.
Rooney broke the deadlock with a sharp 15-yard finish after he was set up by Nani to leave United three points clear at the top of Group F.
United seem to have a habit of winning 1-0 and once again they failed to hit anything like top form against a resolute Roma outfit.
The entire match was a tactical affair in which United demonstrated plenty of intent but very little of the attacking verve which served them so well last season.
Roma, who were knocked off the top of Serie A on Saturday when they slumped to a 4-1 home defeat to Inter Milan, were content to soak up what United threw at them.
Both sides went into the game with stand-in goalkeepers - but neither was seriously tested with long-distance shots from Francesco Totti and Cristiano Ronaldo causing few alarms.
United - with Louis Saha starting a game for the first time since February - began passing the ball around crisply but Roma quickly smothered the Red Devils with Daniele de Rossi brilliantly screening the visiting defence.
Totti's 30-yard free-kick evaded the wall and Tomasz Kuszczak, in for the injured Edwin van der Sar, needed two attempts to cushion the ball to his chest.
United should have gone ahead on 33 minutes when Nani got round the back of the Roma defence only for a carefree Rooney to volley over from a good position.
That apart, Sir Alex Ferguson will have been disappointed to see his side lacking momentum in wide positions with Ronaldo and Nani dropping deep far too often.
If United were too relaxed in the first period, they immediately threatened at the start of the second when a Ronaldo raid down the right was cleared by a relieved Phillipe Mexes in front of his own goal.
Roma spurned their best chance when Giuly set up Totti, who blazed over the advancing Kuszczak from close range five minutes after the restart.
Alberto Aquilani fired another warning to United moments later when he fired narrowly wide from the edge of the box as the Italians sensed a goal was possible.
United were still struggling to get sufficient men forward with Paul Scholes and Michael Carrick content to sit deep in the crowded midfield and unable to make their mark on proceedings.
Nani enjoyed one of his best displays for Man Utd so far
Rooney produced a bright moment when he cut inside the left side of the Roma defence before unleashing a powerful low shot which Curci pushed away for a corner.
Carlos Tevez replaced the tiring Saha and United soon had the ball in the net when the Argentine found Ronaldo, who audaciously back-heeled home from an offside position.
Rooney clinched victory 20 minutes from time with an exquisite finish to raise the roof off Old Trafford.
Carrick found Nani and he cleverly played the ball through to Rooney who turned outside and found the net off the inside of the far post with a crisp 15-yard shot.
Tevez almost made it 2-0 with a sizzling 22-yard effort while Kuszczak did well at the other end to collect a well-struck Simone Perrotta effort.
And United finished the game with 10 men after Cristiano Ronaldo left the field with a head wound which required four stitches.
Roma should have levelled three minutes from time when Totti played the ball back for Mauro Esposito, who carelessly blazed wide from 10 yards with United stretched at the back.
Ferguson said beforehand that he would settle for a 1-0 win. It was not always pretty but it went to script and United are well on their way towards qualifying for the knockout stages.
Manchester United manager Sir Alex Ferguson:
"I'm pleased with the result, it's a fair result, we controlled most of the match, carried a little bit of luck towards the end.
"The second half we improved and the goal was a fabulous goal.
"Luck happens in football, no question about that. I think we got a break in the last 15 minutes of the match when they started to risk a bit."
Roma manager Luciano Spalletti:
"Really this is a match where my players shouldn't be on the beaten side.
"Even when you are playing against opponents of Manchester United's stature, with the players they have."
Man Utd: Kuszczak, O'Shea, Vidic, Ferdinand, Evra, Ronaldo, Carrick, Scholes, Nani (Giggs 79), Saha (Tevez 66), Rooney (Anderson 84).
Subs Not Used: Heaton, Pique, Simpson, Eagles.
Goal: Rooney 70.
Roma: Curci, Cicinho, Mexes, Juan, Tonetto, De Rossi, Aquilani (Pizarro 61), Giuly (Esposito 79), Perrotta, Mancini (Vucinic 74), Totti.
Subs Not Used: Bertagnoli, Antunes, Barusso, Brighi.
Ref: Manuel Enrique Mejuto Gonzalez (Spain).