First set of matches on matchday four has come to an end. Here are the results from all those matches.
1) Inter Milan 1-1 Barcelona: Barcelona secured their place in the Champions League last 16 despite late drama in a 1-1 draw against Inter at a rain-soaked San Siro.
2) Napoli 1-1 PSG: Paris Saint-Germain squandered a chance to ignite their stuttering Champions League campaign as Napoli came from behind to earn a 1-1 home draw on Tuesday.
3) Tottenham 2-1 PSV Eindhoven: Harry Kane inspired a turnaround in the final 12 minutes to transform Tottenham's Champions League outlook as they beat PSV 2-1 to move to within three points of second-placed Inter.
4) Atletico Madrid 2-0 Borussia Dortmund: Atletico Madrid returned to form in Champions League Group A as goals from Saul Niguez and Antoine Griezman earned a 2-0 victory over Borussia Dortmund.
5) Red Star 2-0 Liverpool: Red Star Belgrade blew Champions League Group C wide open and loosened Liverpool's grip on top spot after Milan Pavkov scored a first-half brace in a 2-0 win.
6) Monaco 0-4 Club Brugge: Monaco are facing an early exit from the Champions League after their dismal season hit a new low with a humiliating 4-0 home defeat at the hands of Club Brugge.
7) Schalke 2-0 Galatasaray: Guido Burgstaller and Mark Uth scored in either half as Schalke eased past Galatasaray 2-0 and tightened their grip on second place in Champions League Group D.
8) Porto 4-1 Lokomotiv Moscow: Hector Herrera scored inside 90 seconds of Porto's 4-1 win over Lokomotiv Moscow as Sergio Conceicao's men dumped their opponents out of the Champions League and strengthened their grip on Group D.