West Ham United made it two wins out of two in the Europa League after goals by Declan Rice and Said Benrahma secured a 2-0 home victory over Rapid Vienna, while Leicester City suffered a 1-0 defeat at Legia Warsaw on Thursday.
Marseille‘s home game with Galatasaray, which ended in a 0-0 draw, was marred by crowd trouble with play held up for eight minutes in the first half after rival fans hurled fireworks at each other.
The result put the Hammers top of Group H on six points, three ahead of Dinamo Zagreb who thrashed Genk 3-0 away helped by two goals from striker Bruno Petkovic.
Legia emerged as the surprise Group C leaders on six points after Mahir Emreli’s goal sunk Leicester.
Spartak, second on three points, fought back having fallen behind after 11 seconds when a sloppy error by goalkeeper Aleksandr Maksimenko allowed Eljif Elmas to fire Napoli ahead.
Victor Osimhen pulled one back for Napoli in stoppage time, too late to spare Napoli coach Luciano Spalletti his first defeat in all competitions after taking over in May.
Leicester and Napoli have one point each from their opening two games.
Leverkusen goalkeeper Lukas Hradecky produced a string of superb saves against Celtic in Group G and the hosts were punished by clinical finishing at the other end.
Real Betis also celebrated their second successive win as they beat Ferencvaros 3-1 in Budapest to stay level with Leverkusen on six points.
Rangers completed a poor night for Scottish clubs as they slipped to a 1-0 defeat at Sparta Prague in Group A, with Lyon keeping pole position after a Karl Toko Ekambi brace helped them to a 3-0 victory over Brondby.