Bayern Munich defeated Arsenal 5-2 in their Women's Champions League Group C opener, largely thanks to Pernille Harder's 13-minute hat-trick. Arsenal initially took the lead with Mariona Caldentey's volley, but Bayern equalized before halftime through Glódís Perla Viggósdóttir's header. Sydney Lohmann put Bayern ahead in the second half, but Arsenal's Laia Codina leveled the score again. Harder then dominated the final stages, scoring three times to secure the win for Bayern. This defeat adds pressure on Arsenal's manager Jonas Eidevall, as the team faces a challenging group and high expectations in Europe. Bayern's victory highlights their strong form, having won their last seven matches in all competitions.