- Manchester City vs Borussia Monchengladbach called off due to adverse weather conditions.
- Seconc-half strike from Alexis Sanchez sees Arsenal snatch point from wasteful Paris Saint-Germain.
- Lionel Messi nets three as Barcelona welcome Celtic back to the Champions League.
Here are the full-time scores from around Europe tonight.
Paris Saint-Germain 1-1 Arsenal
Manchester City P-P Borussia Monchengladbach
Barcelona 7-0 Celtic
Basel 1-1 Ludogorets Razgrad
Bayern Munich 5-0 FC Rostov
Dynamo Kiev 1-2 Napoli
Benfica 1-1 Besiktas
PSV Eindhoven 0-1 Atletico Madrid
Full-time: Paris Saint-Germain 1-1 Arsenal
CARDS EVERYWHERE! Olivier Giroud and Marco Verratti are both shown second yellow cards and they are off.
Four minutes of time added on in Paris. Arsenal aren't under any real pressure here.
Moments after Messi was denied a fourth by the post, the Argentine lays one on a plate for Suarez to tap home his second of the night.
Goal! Barcelona 7-0 Celtic (Luis Suarez, 87)
Here's another chance for Arsenal, Mohamed Elneny to replace Ozil. You think Arsene Wenger might be happy to settle for a point here?
Arsenal almost grab another! Sanchez leads a counter attack and slides a brilliant reverse ball into the path of the onrushing Iwobi. He has space in front of him and opens up his body to place it into the far corner, but Areola reads it and saves.
Ospina spurns Cavani again! Just off the bench, Javier Pastore threads through a perfect pass for the striker to run onto. He shrugs off Koscielny and looks to round the Colombia international, but he gets down brilliantly to make a crucial interception.
After countless missed opportunities for PSG, and more specifically, Edinson Cavani, Arsenal spring forward and grab an equaliser! Alex Iwobi nips clear of his marker in the box and lashes one on goal, but it's well blocked by Areola. No matter, just inside the box, Sanchez follows up the rebound with a superb drive into the bottom corner.
Goal! Paris Saint-Germain 1-1 Arsenal (Alexis Sanchez, 76)
Luis Suarez is in on the party at the Nou Camp, taking the ball down on his chest, spinning and firing home.
Goal! Barcelona 6-0 Celtic (Luis Suarez, 76)
PSG make their first chance of the night, Thiago Motta replaces Rabiot.
Cavani misses another great chance. Raboit drives through the heart of Arsenal's defence brilliantly but is finally stopped my Koscielny. The ball breaks favourably in the box to the former Napoli striker who gets one-on-one with Ospina but sees the Arsenal goalkeeper block his effort. It's more good goalkeeping from the Colombian, but Cavani again should have done better.
PSG have lacked that bit of sparkle in this second half but suddenly they come alive again with Aurier and Di Maria combining brilliantly down the right. The full-back breaks into the box to shoot but Ospina is out quickly to block.
Arsenal have been better this second half, but they have been pretty toothless. Arsene Wenger looks to change that by throwing on Olivier Giroud for Oxlade-Chamberlain. Sanchez will move out onto the left.
Welcome back to the Champions League, Celtic. Moments after Andres Iniesta volleyed home a cross from Neymar, Messi has sealed his first hat-trick of the season, slotting home after a neat cut back from Luis Suarez.
Goal! Barcelona 5-0 Celtic (Lionel Messi, 60)
Goal! Bayern Munich 3-0 Rostov (Joshua Kimmich, 56)
Goal! Barcelona 4-0 Celtic (Andres Iniesta, 58)
Verratti has been sensational tonight. Once again, it's him who carves open a golden chance for Di Maria, who has a yard on Monreal as he breaks into the box. The Spaniard does just enough to put him off however as the Argentine tumbles to the ground, appealing for a penalty. No chance.
Meanwhile in Paris, Arsenal have started much better, benefiting from some very loose passing from the home side. Alexis Sanchez still doesn't look at it, however. Up front, he doesn't look comfortable at all.
Messi drives menacingly towards the Celtic box again. Is this his hat-trick? Nope. He has his trailing leg clipped just as he reaches the edge of the box. But surely he'll curl this free-kick in for this third? Again, nope. Instead, Neymar proceeds to bend a superb effort into the top left corner.
Goal! Barcelona 3-0 Celtic (Neymar, 49)