At three goals to the good, it seemed clear this was a match to raise morale at Barcelona ahead of the Clasico, and a fine way to start their Champions League campaign. That changed when Gerard Pique was sent off, pulling Tokmac Nguen down in the area and giving away a penalty.
Neto; Sergi Roberto (Junor, 62'), Piqué, Lenglet, Dest; Pjanic (Sergio, 75'), Frenkie de Jong; Trincao (Dembélé, 62'), Coutinho, (Araujo, 70') Ansu (Pedri, 62'); y Messi.
Dibusz; Botka (Lovencrics, 77'), Blazic, Kovacevic, Civic (Heister, 63'); Kharatin, Laidouni (Somalia, 63'), Siger; Zubkov (Mak, 70'), Isael y Nguen (Boli, 70').
1-0 M.27 Messi (p.). 2-0 M.41 Ansu. 3-0 M.51 Coutinho. 3-1 M.70 Kharatin (p.). 4-1 M.83 Pedri. 5-1 M.88 Dembélé.
Sandro Schärer (Suizo). TR: PIqué (68'). TA: Laidouni (32'), Civic (44').
Camp Nou. Partido a puerta vacía.
The dismissal means Pique will not be available for next week’s trip to face Juventus in Turin, a far graver repercussion than missing the final 20 odd minutes of this group stage opener, which Barcelona went on to seal comfortably.
The Hungarians started well with Nguen having a screamer ruled out for offside, while Isael smashed an effort against the crossbar.
However Lionel Messi put Barcelona ahead from the penalty spot after he was felled in the box, and Ansu Fati netted the second after a fine chipped ball from Frenkie de Jong sent him in.
The third came just after half-time when Messi fed Fati, who back heeled the ball to Coutinho, and the Brazilian drilled in at the near post with the help of a slight deflection.
That was game over, or at least it should have been, but Pique tugged back Nguen in the box when he should have let the forward run through. Ihor Kharatin sent Neto the wrong way from the penalty spot.
That made the final stages a little tougher for Barcelona too but they largely held the visitors at bay to claim the three points, with Pedri adding the fourth after good work by substitute Ousmane Dembele to set him up.