Emmanuel Boateng put up a fine performance for UD Levante as they handed Barcelona a 2-1 defeat in the first leg of the last 16 on Thursday.
The Frogs took only four minutes to move ahead, with Erick Cabaco rising highest to head home the opening goal from a wide free-kick against a makeshift Barcelona defence.
The Ghanaian international had a chance to double their lead few minutes later but saw his effort saved by Jasper Cillessen.
A defence-splitting move by Boateng in the 18th minute put Borja Mayoral through who made no mistake to make it 2-0.
Barça had to wait until the 85th minute before they finally got one back, and the all-important away goal will count for diamonds in the second leg. Coke brought down Denis Suárez and Coutinho stepped up to give the visitors the vital away goal.
The second leg takes place at the Nou Camp next Thursday.