Matchday 3 of the 2016/17 UEFA Champions League was completed on Wednesday night with the second lot of fixtures.
In Group A, Arsenal flexed their muscle with a dominant 6-0 demolition of Bulgarian minnows Ludogorets Razgrad at the Emirates Stadium.
A second-half hat-trick from Mesut Ozil - his first in professional football - put the gloss on an already successful night which had the Gunners on fire with quality goals from Alexis Sanchez, Theo Walcott and Alex Oxlade-Chamberlain prior to the the German's treble.
In Paris, PSG joined Arsenal on seven points courtesy of a 3-0 victory over Swiss champs FC Basel.
Angel Di Maria, Lucas Moura and Edinson Cavani were all on target as Unai Emery's men overcame a tardy start to power past Basel.
In Group B, Besiktas led on three occasions to eventually come away with a stirring 3-2 triumph over Napoli at the Studio San Paolo.
Vincent Aboubakar was the hero for the Turkish giants with a brace as they moved to second place on the table, where they sit just a point behind Napoli.
Benfica picked up their first win of their top flight European campaign with a 2-0 win over Dynamo Kyiv in Ukraine to keep their qualifying hopes alive.
Group C saw Barcelona put Manchester City to the sword with a 4-0 pounding at the Nou Camp.
It was a dramatic night on Pep Guardiola's return to Catalonia which saw City keeper Claudio Bravo sent off for a brain fade before Barca turned on the style through Lionel Messi, who helped himself to get another hat-trick, while Neymar was also on target despite seeing a late penalty saved by Willy Caballero.
The win has Barcelona, who saw defender Jeremy Mathieu also sent off, sitting pretty on top of the standings with nine points, five clear of City, and six ahead of Borussia Monchengladbach.
The Germans beat Celtic 2-0 at Parkhead to pick up their first lot of three points for the tournament.
And Group D had Atletico Madrid winning 1-0 at FK Rostov, thanks to Yannick Ferreira Carrasco's second-half winner, to remain unbeaten and at the top of the standings.
German giants Bayern Munich scored twice in each half to see off PSV Eindhoven 4-1 at the Allianz Arena to stay within three points of Atleti.
The next Group A to D fixtures take place around Europe on Tuesday, November 1.
2016/17 UEFA Champions League - group stage
Group A
Arsenal (ENG): 6 (Alexis Sanchez 12, Theo Walcott 42, Alex Oxlade-Chamberlain 46', Mesut Ozil 56'/83'/87')
Ludogorets Razgrad (BUL): 0
Emirates Stadium, London, England - 59,944
PSG (FRA): 3 (Angel Di Maria 40', Lucas Moura 62', Edinson Cavani (PEN) 90+3')
FC Basel (SUI): 0
Parc des Princes, Paris, France - 46,488
Group B
Napoli (ITA): 2 (Dries Mertens 30', Manolo Gabbiadini (PEN) 69')
Besiktas (TUR): 3 (Adriano 12', Vincent Aboubakar 38'/86')
Stadio San Paolo, Naples, Italy - 28,502
Dynamo Kyiv (UKR): 0
Benfica (POR): 2 (Eduardo Salvio (PEN) 9', Franco Cervi 55')
Olympic Stadium, Kyiv, Ukraine - 25,991
Group C
Barcelona (ESP): 4 (Lionel Messi 17'/61'/69', Neymar 89', missed penalty: Neymar 87', red card: Jeremy Mathieu 73')
Manchester City (ENG): 0 (red card: Claudio Bravo 53')
Camp Nou, Barcelona, Spain - 96,290
Celtic (SCO): 0
Borussia Monchengladbach (GER): 2 (Lars Stindl 57', Andre Hahn 77')
Celtic Park, Glasgow, Scotland - 7,814
Group D
FK Rostov (RUS): 0
Atletico Madrid (ESP): 1 (Yannick Carrasco 62')
Olimp-2, Rostov-on-Don, Russia - 15,400
Bayern Munich (GER): 4 (Thomas Muller 13', Joshua Kimmich 21', Robert Lewandowski 59', Arjen Robben 84')
PSV Eindhoven (NED): 1 (Luciano Nursing 41')
Allianz Arena, Munich, Germany - 70,000