Cristiano Ronaldo missed an early penalty as Manchester United held Barcelona to a goalless draw in their Champions League semi-final first leg clash at the Camp Nou.
In a cagey game, Frank Rijkaard's team had most of the possession but struggled to create many clear-cut chances, particularly after the outstanding Lionel Messi was substituted early in the second half.
United suffered a blow before kick-off when Nemanja Vidic was rushed to hospital with suspected gastro-enteritis. Owen Hargreaves started the game at right-back with Wes Brown partnering Rio Ferdinand at the heart of the defence.
In only the second minute of the game United were given the opportunity to make the perfect start when the referee awarded them a penalty after Gabriel Milito was adjudged to have handled the ball.
However, Ronaldo side-footed his spot-kick wide as Victor Valdes went the other way.
Unperturbed, United edged the opening stages before slowly losing the initiative as they were pegged further and further back.
Messi continually attempted to prise open United's defence while Yaya Toure was excellent in his holding midfield role but too often Barca's attacks were too laboured.
Barca kept the ball well but struggled to create a clear-cut opening despite all their possession.
United thought they should have had a second penalty on the half-hour when Andres Iniesta's terrible pass picked out Ronaldo. The Portugal international tumbled inside the area under Rafael Marquez's challenge but there was to be no penalty this time.
Samuel Eto'o had a half-chance after being found by Messi but, before the Cameroon international could get his shot in, Brown got across to block the effort.
Just before half-time Ferdinand showed his pace to stop Eto'o racing towards goal but the best spell of the match came early in the second period.
Poor play by Brown let in Eto'o who would surely have won a penalty had he gone down under Ferdinand's challenge. The striker stayed on his feet though and was unable to pull the back for Messi.
Eto'o then fired into the side-netting when he seemed certain to score while at the other end Michael Carrick should have crossed into the six-yard area rather than trying to shoot from a tight angle.
After Messi went off just after the hour mark, the game petered out as both sides seemed to settle for a goalless draw and they will now try again in six days' time at Old Trafford.