The French league leaders went ahead in the 18th minute when Jule Brand scored with the visitors' only shot on target in the first half.

But the Gunners were level shortly before the hour mark courtesy of an own goal from Ingrid Engen after goalkeeper Christiane Endler failed to gather the ball.

And they took the lead when Olivia Smith took advantage of another mix-up at the back late in the game.

The two sides met at the same stage of the competition last season, with Arsenal winning 5-3 on aggregate before going on to lift the trophy with victory against Barcelona in the final.

Lyon drew first blood at the Emirates on Sunday when Brand surged forward and cut inside before beating Arsenal goalkeeper Daphne van Domselaar with a confident finish.

The home side thought they had been offered a way back into the game when they were awarded a penalty five minutes after the restart but the decision was overturned after a VAR check.

But Arsenal were level in the 58th minute when Mariona Caldentey's low free-kick somehow made its way into the net.

Lyon's Endler mishandled the ball and the unfortunate Engen touched it into her own goal.

Kadidiatou Diani rattled the crossbar as the French team threatened to re-take the lead but it was Arsenal who scored again.

Endler and Engen had a moment of miscommunication and Smith showed perseverance to poke the ball home in the 83rd minute.

The second leg takes place in Lyon next weekend.