Neymar turned on the style as Paris St Germain got their campaign back on track with a 6-1 victory over Red Star Belgrade at Parc des Princes.
The Brazil forward scored a hat-trick, two of them free-kicks, as the Ligue 1 champions bounced back from their 3-2 defeat at Liverpool in their opening Group C fixture.
Edinson Cavani, Angel Di Maria and Kylian Mbappe also scored for Thomas Tuchel's side while the Serbian outfit grabbed a second-half consolation through Marko Marin.
Inter maintained their perfect start in Group B with a 2-1 victory at PSV Eindhoven. Pablo Rosario got the Dutch side off and running but Radja Nainggolan levelled for Inter with a 20-yard strike just before the break.
Mauro Icardi then put the Nerazzurri in front on the hour mark after rounding keeper Jeroen Zoet and slotting into the empty net.
Atletico Madrid and Borussia Dortmund both maintained their 100 per cent record in Group A with home victories against Club Brugge and Monaco respectively.
Antoine Griezmann put Atleti ahead after 28 minutes before a stunning strike from Arnaut Danjuma brought Club Brugge level 11 minutes later.
Griezmann's second of the night after 67 minutes restored Madrid's advantage before Koke rounded off a 3-1 win for Diego Simeone's side.
At the Westfalenstadion, substitute Jacob Bruun Larsen, Paco Alcacer, who had earlier missed a penalty, and Marco Reus wrapped up Dortmund's comfortable 3-0 victory over Monaco.
In Group D, Moussa Marega's second-half header earned Porto a 1-0 win at home to Galatasaray while Weston McKennie left it late to secure Schalke a 1-0 victory at Lokomotiv Moscow.
