Last update on. From the section Women's Football
Asisat Oshoala, the BBC's first Women's Footballer-of-the Year 2015
Arsenal lost their first match since February when Barcelona's Asisat Oloala, a member of the Women's Champions League Group C, hailed her old club.
Mariona Caldentey got the rebound for Oshoala's first shot.
Nigerian Oshoala sprinted down the right wing, squared it for Alexia Putellas, who slotted home. She also added a third from a superb Mariona through ball.
Frida Maanum provided consolation for visitors, before Lieke Martens added the fourth for holders.
Manuela Zinsberger saved Putellas' penalty.
26-year-old Oshoala played for Arsenal between March 2016 and February 2017. She helped them win the FA Cup but did not celebrate their goal at the Johan Cruyff Stadion.
Arsenal took 55 minutes to score a goal, with Vivianne's poor effort going straight to Sandra Panos.
As the game progressed, the Gunners created more opportunities with Nikita Paarris scoring a goal that cleared the line just before Maanum struck.
Jonas Eidevall's Gunners were one the most form European teams when they arrived at the game. They had eight wins in eight games across all competitions this season and scored at least three goals in each match.
They were unbeaten in all 20 games, dating back to February.
They were also defeated by Barcelona, who had won five of their matches in the league. This was their first game in which they scored less than five goals.
Barca, European champions, showed why it will be difficult to stop this season. They should have extended that scoring run with 35 shots and 14 on target.
The Gunners will host Hoffenheim, a German side, in the Champions League on Thursday 14 October. Barcelona will face Koge in Denmark.
In Tuesday's other game in Group C, Hoffenheim defeated Koge 5-0.
