Barcelona defeats Werder Bremen
Barcelona's Lionel Messi then made a speedy impact after coming on in the 66th minute, the gifted Argentine teenager winning a penalty for Ronaldinho to convert 11 minutes later that clinched victory for the Catalans.
Earlier Bremen's Ivan Klasnic twice failed to make contact when presented with chances in front of goal.
Nelson Valdez inexplicably fired over from a couple of meters and Johan Micoud clattered a shot against the post -- all before the first half was over.
Barcelona's 1-0 lead at half-time was scarcely credible, given the level of control exerted by the home side after Deco had put the visitors ahead.
The Bremen defense made a mess of clearing Giovanni van Bronckhorst's aimless cross from the left, the ball fell to the Portugal international and his shot took a deflection off Frank Baumann to leave keeper Andreas Reinke wrong-footed.
Bremen took a while to react but when they did it was with real bite.
Midfield hardmen Baumann and Torsten Frings took Deco and Xavi out of the game and Klasnic and Valdez set about wreaking havoc up front.
The equalizer should have arrived in the 27th minute when Valdez turned Van Bronckhorst out by the right touchline and crossed low for Klasnic, who failed to get in a shot.
The chances came thick and fast thereafter, with a Samuel Eto'o shot at the keeper the only action at the other end.
Klasnic let slip another opportunity when he raced on to a loose Deco pass two minutes later and in the 33rd minute Valdez missed the best chance of the night, scooping the ball over from Klasnic's ball to the far post.
Frings volleyed just wide, Micoud shot a metre over the bar and the Frenchman closed out the half by smacking the post with Victor Valdes well beaten.
Barcelona could only improve in the second half and they had a chance to go 2-0 up when Deco found himself in another good position and hit the outside of Reinke's left-hand post.
Bremen's momentum gradually failed and they were hit a second time as Messi, unable to play in the Spanish League because of a dispute over his status, made the most of his first chance to shine this season to win the penalty with a clever run into the box.