Lionel Messi helped give Celtic another harsh Champions League lesson with a hat-trick as Barcelona thrashed the Hoops 7-0 in their Group C opener at the Nou Camp.
This was the Hoops' first game back in the group stage of the competition for three seasons, their most recent match ending in a 6-1 defeat the same venue, and it was another chastening evening for the Scottish champions.
Brazilian star Neymar set up Lionel Messi for the opener in the third minute and the Barca captain added a second from close range in the 27th minute after Parkhead striker Moussa Dembele had a penalty saved by Marc-Andre ter Stegen.
Neymar added a third five minutes into the second half with a wonderful free-kick, substitute Andres Iniesta scored with an even better volley and then Messi tapped in for his third with half-an-hour to play.
As Celtic continued to chase shadows Luis Suarez grabbed a double to give Celtic their heaviest European defeat.
Hoops boss Brendan Rodgers' bid to contain Barca included giving a debut to Costa Rica defender Cristian Gamboa, signed from West Brom at the end of the transfer window, and the 26-year-old was one of two changes in a 5-4-1 starting formation, with wide-man Patrick Roberts also coming in.
After scoring a hat-trick in the 5-1 win over Rangers, and in the absence of injured Leigh Griffiths, Dembele was again asked to lead the line.
Bayern Munich 5 - 0 FK Rostov: Joshua Kimmich at the double for five-star Bayern
Midfielder Joshua Kimmich continued his goal rush as he claimed a double in Bayern Munich's 5-0 Champions League demolition of FC Rostov.
The 21-year-old took his tally for club and country to four goals in three games, having only scored his first for his club against Schalke on Friday, as Carlo Ancelotti's men romped to a record 13th successive home victory in the competition.
Robert Lewandowski opened the scoring from the penalty spot and Thomas Muller extended the lead in injury-time at the end of the first half, but it was Kimmich who wrapped up the first three points of his side's Group D campaign with a brace inside seven second-half minutes before substitute Juan Bernat added a fifth at the death.
Five-times winners Bayern started in confident mood as they looked to sweep the Champions League newcomers aside, and defender Javi Martinez had already tested goalkeeper Soslan Dzhanaev with a 15th-minute header when Lewandowski signalled his own intent with a shot six minutes later.
Dortmund six-shooters wreck Legia's comeback
Legia Warszawa's return to the group stage after 21 years away was spoiled by Borussia Dortmund, who scored three early goals on their way to a 6-0 Group F victory