19.45 BST - Champions League matchday three
Full-time: Arsenal 6-0 Ludogorets Razgrad
Full-time: Paris Saint-Germain 3-0 FC Basel
Full-time: Dynamo Kiev 0-2 Benfica
Full-time: Napoli 2-3 Besiktas
Full-time: Barcelona 4-0 Manchester City
Full-time: Celtic 0-2 Borussia Monchengladbach
Full-time: Bayern Munich 4-1 PSV Eindhoven
Full-time: C Rostov 0-1 Atletico Madrid
That is all from us for now, but make sure you check back in with IBTimes UK tomorrow night as we bring you live coverage of the Europa League. Manchester United host Robin van Persie and Fenerbahce, while Claude Puel's Southampton travel to the San Siro to take on Inter Milan.
Don't miss it. Goodnight.
The Arsenal juggernaut rolls on unabated after the Gunners put Ludogorets to the sword with six goals and a first career hat-trick for Mesut Ozil. They continue to top Group A ahead of PSG courtesy of their superior goal difference. Wenger's men, who have now won seven straight matches in all competitions travel to Bulgaria in 13 days time.
So a truly chastening evening for Guardiola, who returns to the Nou Camp and suffers the joint-heaviest defeat of his stellar managerial career so far.
City did not actually play particularly badly for much of this game, but multiple defensive errors and that idiotic dismissal by Bravo really served to undermine their efforts. Pep will be hoping for a much better outcome when Barcelona, who never really needed to get out of third gear here, visit the Etihad Stadium for the return fixture on 1 November.
City remain second in Group C, five points adrift of tonight's opponents after one win, one draw and one defeat from their opening three matches. Celtic, meanwhile, sink to the bottom after their disappointing home defeat to an out of form and undermanned Gladbach side in Glasgow.
Barcelona 4-0 Manchester City
Celtic 0-2 Borussia Monchengladbach
Bayern Munich 4-1 PSV Eindhoven
FC Rostov 0-1 Atletico Madrid
Arsenal 6-0 Ludogorets Razgrad
Paris Saint-Germain 3-0 FC Basel
Dynamo Kiev 0-2 Benfica
Napoli 2-3 Besiktas
Goal: Paris Saint-Germain 3-0 Basel (Edinson Cavani)
Looking to atone for that penalty miss, Neymar completes the rout by slaloming past Gundogan and Stones before wrapping a right-footed shot beyond Caballero.
What a lovely goal. Guardiola's humiliation is complete.
Goal: Barcelona 4-0 Manchester City (Neymar)
Goal: Napoli 2-3 Besiktas (Vincent Aboubakar)
Messi weaves his way through a hapless City defence before being felled by a sliding challenge from Clichy.
Referee Mazic immediately points to the spot and Caballero saves Neymar's penalty low to his right.
A brief moment of cheer for the visitors at least.
Penalty to Barcelona
Utterly ruthless from Arsenal and Ozil joins Messi in completing his treble. Perez is again the provider, teeing up his teammate with a lofted pass that is volleyed low past Stoyanov at his near post.
That is Ozil's first career hat-trick in senior football.
Goal: Arsenal 6-0 Ludogorets (Mesut Ozil)
Arsenal pile on yet more misery in north London. Oxlade-Chamberlain releases substitute Lucas Perez, who picks out Ozil all alone in the penalty area.
The German playmaker drives his effort into the ground and it loops up and into the back of the net.
Goal: Arsenal 5-0 Ludogorets (Mesut Ozil)
Goal: Bayern Munich 4-1 PSV Eindhoven (Arjen Robben)
Goal: Celtic 0-2 Borussia Monchengladbach (Andre Hahn)
Speaking of ridiculous red cards, that is utterly brainless from Mathieu. The centre-back, who replaced Pique in the first half, receives his second caution in quick succession for scything down Sterling near the touchline.
Enrique will be rightly furious with his defender, who should know better. We are level at 10-men apiece.
Red card: Jeremy Mathieu (Barcelona)
City are at sixes and sevens at the back. That is music to the ears of Messi, who taps home Suarez's pass from near the penalty spot to complete his 37th - yes, 37th - Barcelona hat-trick.
It's a testament to that unbelievable scoring prowess that he has still managed to notch three tonight, despite not playing particularly brilliantly according to his usual high standards.
IBTimes UK sport editor Nick Howson at the Emirates Stadium:
Arsenal have been at their clinical best at the start of this second half and Ludogorets are now on the wrong end of a rout. Oxlade-Chamberlain made it three before Mesut Ozil staked his claim for touch of the match with a delightful piece of control before making it four.
Goal: Barcelona 3-0 Manchester City (Lionel Messi)
Goal: Napoli 2-2 Besiktas (Manolo Gabbiadini)
Goal: Dynamo Kiev 0-2 Benfica (Franco Cervi)