Helsinki 0-6 Barcelona
Munir El Haddadi offered a timely reminder of his qualities as he scored a first-half double to help Barcelona to a 6-0 win over Helsinki on Saturday
Sergi Roberto, Gerard Pique, Marc Bartra and Sandro were also on target for the Camp Nou team in the Finnish capital.
But it was the teenage Munir and fellow forward Rafinha who stole the headlines with a stirring first-half display to give Barcelona a four-goal advantage at the interval.
Barcelona head coach Luis Enrique gave Jordi Masip a start in goal ahead of summer signings Claudio Bravo and Marc-Andre ter Stegen.
The Camp Nou boss had left Lionel Messi and Neymar at home, and gave Rafinha, Pedro and Munir starts up front. Andres Iniesta captained the team in the Finnish capital.
And Munir rewarded Enrique with the opening goal in the fifth minute after collecting a superb ball from his skipper Iniesta before firing home.
Four minutes later, Barcelona were two goals ahead after Sergi Roberto pounced on a neat interchange with Munir before finding the net.
In the 17th minute, Barcelona effectively sealed the win with a third goal, and Munir's second of the game after the 18-year-old headed home a superb cross from Rafinha.
The teenager was enjoying a storming match for the La Liga giants and offered a timely reminder of his qualities in the absence of Messi and Neymar, and ahead of the arrival of Luis Suarez.
But it was Barcelona defender Gerard Pique who added the fourth goal of the afternoon. Munir began the move after a blocked effort and played the ball to Pedro, who found Pique, and the centre-half slotted home.
It was no surprise that Helsinki would make an early change, but few people would have envisaged a switch in goalkeepers. Michael Tornes was replaced by Carljohan Eriksson.
This was a much-improved Barcelona display, though, after the lacklustre performance in the defeat to Napoli in midweek.
Masip was finally forced into some action late in the first half, but his save from Macoumba Kandji in the 40th minute was comfortable.
The half-time whistle came as a blessing for the home side, who had been completely overrun and outclassed by Barcelona.
Pique and Iniesta made way for Edgar le and Ivan Rakitic at the start of the second half, and just four minutes after the break, Barcelona were 5-0 up. Rakitic swung over a free-kick, and Bartra was the first to rise to head home.
Sergio Busquets had taken the captain's armband after the half-time withdrawal of Iniesta, but Helsinki were looking a more organised outfit in the second period.
In the 58th minute, Enrique made a mass change with five switches to his team.
Masip needed to be alert in the 76th minute to deny Oussou Konan, before Barcelona substitute Gerard Deulofeu saw his shot saved by Eriksson's legs at the other end of the field.
With nine minutes remaining, Barcelona made it 6-0 when Sandro fired home right-footed angled drive.
It was, ultimately, a win gained with ease by Barcelona as they bounced back from the disappointing midweek loss to Napoli in style.
Selected player ratings
Munir El Haddadi Mohamed: A+
The Barcelona youngster took full advantage of the absences of Messi, Neymar and Suarez to remind Luis Enrique of his qualities. Two goals in the first period were just reward for a sublime display.
Another Barcelona player to prove his worth in Helsinki. The Brazil-born forward looks supremely talented and enjoyed a fine opening period, which included a superb dribble through five Helsinki players.
Jordi Masip: B
He was barely troubled throughout the game as he stood in for Bravo and Ter Stegen, but his handling looked composed when required.