Arsenal reached their first Women’s Champions League final in 18 years on Sunday, taking down French powerhouse Lyon with a remarkable 4-1 away win.

Lyon manager Joe Montemurro, who used to coach Arsenal, said the game’s outcome was “unexplainable,” with the French side having entered with a 2-1 advantage from the first leg only to los 5-3 on aggregate.

“Until today we were unbeaten, for what happened today was a little bit unexplainable,” Montemurro told DAZN. “We weren’t calm enough to play our game and were beaten by the better team.”

Goals from Mariona Caldentey, Alessia Russo and Caitlin Foord — after an own goal from Lyon goalkeeper Christiane Endler — gave Arsenal a 5-3 win on aggregate and set up a showdown with defending champions Barcelona in the final.

Arsenal captain Kim Little lauded the work of the squad, who are looking to add Arsenal’s second European title, with their 2007 triumph the only by a British side in women’s football.

“It means a lot to this incredible football club. I’m excited and looking forward to representing this club in the final,” Little told DAZN. “We have belief in this group and we are very good at executing our game plans. We did it fairly well in the first leg but not well enough — today we executed it very well and thoroughly deserved to win.”

Arsenal’s feat of reaching the final was made even more impressive by the fate of Women’s Super League rivals Chelsea, who were handily beaten by Barça in each of their two semifinal legs.