Asisat Oshoala scored one and made two as holders Barcelona kicked off their Women's Champions League campaign with a commanding 4-1 win over Arsenal at the Estadi Johan Cruyff on Tuesday.
Oshoala laid on goals for Mariona Caldentey and Alexia Putellas before the break and then added the third herself in the second half as Women's Super League leaders Arsenal tasted defeat for the first time this season.
Frida Maanum did pull one back for the visitors but any hopes of an unlikely comeback were ended when Lieke Martens scored Barca's fourth inside the final 10 minutes. Alexia spurned the chance to make it five when she saw a stoppage time penalty saved by Manuela Zinsberger.
The competition has been revamped this season to feature a 16-team group stage for the first time ever. Arsenal, therefore, will have another chance to get their European campaign up and running next week when they host Hoffenheim, while Barca, who beat Chelsea in last season's final, travel to HB Koge next.
The gap in quality between the two teams here was evident in a first half in which Arsenal didn't register a single shot on goal.
Barca, who replaced treble-winning coach Lluis Cortes with Jonatan Giraldez in the summer, were dominant from the off. Oshoala dragged an early chance wide for the European champions and Marta Torrejon was denied by Zinsberger as the pressure mounted.
The breakthrough eventually came in the 30th minute. Zinsberger could only parry a fierce drive from Oshoala and Caldentey was quickest to react to the loose ball.
Captain Putellas, recently named UEFA's Women's Player of the Year for last season, netted the second soon after, converting from close range after Oshoala pulled the ball back. The strength and depth of this Barca side was demonstrated by the fact the two players on the UEFA podium with Putellas last month, Martens and Jenni Hermoso, both started this game on the bench.
However, it was Nigerian striker Oshoala who continued to torment Arsenal after the break. She added the third after being played through by Caldentey in the 47th minute and it should have been four moments later when midfielder Aitana Bonmati ran though. Zinsberger saved again, though.
Arsenal, who have scored 16 goals in four league games this season, had their best spell after falling three behind. Nikita Parris had a shot cleared off the line by Mapi Leon before Jonas Eidevall's side eventually got on the scoresheet from their next attack.
Tobin Heath's free-kick wasn't properly dealt with and Maanum bundled the ball over the line from close range.
That goal sparked Barca back into life. Dutch international Martens had already had three chances after coming on as a second-half substitute when she eventually dinked the ball over Zinsberger to seal the three points.
Barca, who ended the game with 37 shots to Arsenal's seven and 65% of the possession, could have made it five, but Putellas saw a late penalty saved by Zinsberger.