Lionel Messi moves closer to matching Barcelona 's record in the Champions League . In Group H , Atletico Madrid beat Zenit St. Petersburg 3-1 to maintain its impressive home record in Europe and FC Porto edged debutant Austria Vienna 1-0 . Arsenal , a day after Cristiano Ronaldo 's hat - trick , scores three goals as Barcelona beat Ajax . Chelsea suffers a shock 2 - 1 defeat at home to Basel after taking the lead . Last season 's finalist , Borussia Dortmund , loses 2 - 1 at Rafael Benitez 's Napoli .
Lionel Messi moves closer to matching Barcelona 's record in the Champions League . Arsenal , a day after Cristiano Ronaldo 's hat - trick , scores three goals as Barcelona beat Ajax . Chelsea suffers a shock 2 - 1 defeat at home to Basel after taking the lead . Last season 's finalist , Borussia Dortmund , loses 2 - 1 at Rafael Benitez 's Napoli .