Cristiano Ronaldo struck twice on his return to Spain as Juventus crushed a dismal Barcelona and took top spot in Champions League Group G.
An early, very dubious, penalty was given after Ronald Araujo clashed with Ronaldo in the box and he sent Marc-Andre ter Stegen the wrong way.
Barcelona were shaken and Weston McKennie volleyed in well for the second after a neat Juan Cuadrado cross.
That’s when Leo Messi woke up but he was repeatedly denied by 42-year-old veteran Gianluigi Buffon in goal for Juventus.
Ronaldo won the battle on the night as he drilled home again from the penalty spot after Clement Lenglet’s handball in the second half.
Barcelona had plenty of the ball after the break but little incision on a disappointing night.
It was their first home group stage defeat since 2009 and first at home at any point in the tournament since Bayern Munich won at Camp Nou in 2013.
Ronaldo, 35, may not face Messi, 33, again in the tournament and the Portuguese forward had the last laugh here, despite Messi having seven shots on goal, all saved by Buffon.
Antoine Griezmann headed against the crossbar from a Messi cross but Barca were getting nowhere.
“We were not good enough, they over-ran us in the first half, we lacked everything,” Griezmann told Movistar. “A lack of attitude, desire, wanting to run, defending, attacking, everything was bad.”