Dublin, Ireland: A blond-haired Lionel Messi failed to get on the scoresheet but it hardly mattered as under-strength Barcelona taught Celtic a footballing lesson in a Dublin friendly on Saturday.

Strikes by Arda Turan and Munir El Haddadi, and an own goal by Efe Ambrose -- all before the break -- were enough to earn a 3-1 victory for Luis Garcia's men in what was their first game back after the summer.

Leigh Griffiths had replied to Turan's opener, but boss Brendan Rodgers will be concerned with how vulnerable his defence looked once again, ahead of Celtic's crucial Champions League third qualifying round clash with Astana on Wednesday.

The tie is delicately balanced at 1-1 ahead of the second leg at Parkhead.

Barcelona came to Dublin without Andres Iniesta, Gerard Pique, Sergio Busquets, Javier Mascherano, Claudio Bravo and Jordi Alba, who aren't back in training until tomorrow, while Neymar is preparing for the Olympics in Brazil.

But there was more than a sprinkling of quality with Messi and Luis Suarez bringing enough star power to help fill over 47,000 seats at Lansdowne Road.

Rodgers made four changes to the side that drew at Astana last Wednesday, but new signing Kolo Toure did not travel.

Things had looked good for Celtic early on and they almost opened the scoring after just 13 seconds when Patrick Roberts capitalised on a Jeremy Mathieu slip, cut inside -– Messi-style -– but sent his curling effort inches wide of Jordi Masip's goal.

With Roberts a constant threat, Celtic had the bulk of the early chances, but when the opening goal came it was from the Spanish champions, Turan firing home powerfully from the edge of the box.

Roberts continued to get the fans on their feet, delivering some of the slalom runs many would have come to see Messi perform.

But when Celtic scored the assist came from a Barcelona error, handing Griffiths a tap-in from five yards out.

Ambrose and keeper Craig Gordon then conspired to concede a howler, with the centre-half stretching to intercept a harmless cross and sending it beyond the hapless Gordon.

Barcelona added a third before the break as Celtic's defence collapsed again, with Suarez nipping behind all too easily, before nutmegging Ambrose and squaring to Munir, who was all alone to slot home.

Both sides swapped their entire starting 11s as the second half passed, with a quiet Messi -- sporting his new peroxide blond hair -- going off at the break.