Barcelona avenged the demons of 2012 by squeezing past Celtic with a 1-0 scoreline.
The away side dominated the ball for long periods but lacked cutting edge, and it wasn't until Scott Brown was shown a straight red card that the tide began to turn.
Cesc Fabregas netted the only goal of the game after wonderful work from Neymar and Alexis Sanchez. Fraser Forster made three glorious saves late on to keep the deficit at just a single goal.
Barca started with one minute and 50 seconds of patient possession, testing Celtic to see how aggressive they'd be.
The home side stayed compact, protected their final third and refused to be drawn out by any of the wall passes attempted. Barca's two eventual corners came to nothing.
That set the tone for the first half, with Gerardo Martino's side enjoying the lion's share of possession, but doing very little with it. On the whole, Who Scored? credited Barcelona with 82 percent of possession.
Georgios Samaras had the first good chance of the half after Anthony Stokes' cutting pass saw him in behind Gerard Pique, but Victor Valdes narrowed down the angle expertly and saved the shot with ease.
Neymar, Andres Iniesta and Fabregas all tried their luck on Forster's goal, and it was the Brazilian who came closest after clipping a Dani Alves cross just wide of the post.
Barca ended the first half in the ascendancy, but failed to notch a goal and looked a little disjointed on the whole. Neymar has developed great chemistry with Cesc the midfielder, but not Cesc the false nine.
The second period took the same shape as the first and Celtic again looked their most threatening early on. Some uncertain work at the back from Pique almost saw Stokes in and Scott Brown fired well over from 20 yards out.
On 60 minutes, a turning point in the game occurred.
With Neymar steaming forward down the left flank, Brown chopped him down cynically and proceeded to kick him in the back as he ran past. The referee showed no hesitation, opting to send the captain off with a straight red card.
Holding Barca at bay became harder, and despite Neil Lennon making wise substitutions to place fresh legs in both midfield and defence, it wasn't long until the Blaugrana broke the deadlock.
Neymar surged forward straight from a quick free-kick, picked out Alexis Sanchez on the right, who in turn sent in a perfect cross for Cesc Fabregas. The Spaniard nodded home expertly at the far post, prompting a heavy round of boos from the home side.
Forster pulled off an outstanding double save on Neymar and Sanchez as Barca pushed for more. In stoppage time, the keeper bested the Brazilian yet again in a one-on-one situation.
Celtic's late surge for an equaliser was stifled by a Samaras foul. Ultimately, the home fans filed out aggrieved, but proud of their side's effort.
Key Player Grades
Neymar, Barcelona: B+
The Brazilian provided plenty of running and caused Brown's sending off—a turning point in the game. Had it not been for The Great Wall, he could have bagged a brace.
Virgil van Dijk, Celtic: B-
Celtic defended excellently as a team and Van Dijk was central to the system Neil Lennon put in place. He was uncompromising in the air and strong in the challenge, shrugging Barca players off with ease.
Full Player Grades
Barcelona host Real Valladolid on October 5 at Camp Nou, while Celtic entertain Motherwell earlier that same day.