Spanish sides scored four wins out of four in their respective Champions League clashes this week, with Barcelona thrashing Manchester City 4-0 and Real Madrid putting five past Legia Warsaw.
Lionel Messi put in a stellar performance, scoring a hat-trick to help his side beat Manchester City 4-0 on Pep Guardiola's return to the Camp Nou on Wednesday night.
City goalkeeper Claudio Bravo was sent off in the 53rd minute for a deliberate handball and from then on Barça ruthlessly made their numerical advantage count as Messi struck twice in eight minutes to notch up his 37th club treble.
Jeremy Mathieu's dismissal for two bookable offences failed to derail the hosts as Neymar, having missed an 87th-minute penalty, atoned with Barça's fourth a minute from time.
Victory moves Barça five points clear of second-placed City in Group C.
Real Madrid remain second in Group F after a thrilling 5-1 win over a spirited Legia Warsaw at the Bernabéu on Tuesday.
First-half goals from Gareth Bale, a Tomasz Jodlowiec own goal and Marco Asensio put Real in control despite Miroslav Radovic's 22nd-minute penalty threatening to spark a fightback for the away side.
Substitutes Lucas Vázquez (pictured) and Álvaro Morata put the game beyond doubt in the second half as Zinedine Zidane's side cruised to victory.
The result means Real Madrid are level with Borussia Dortmund on seven points, while Legia remain rooted to the bottom of the table with no points from their opening three matches.
The Polish side also face being kicked out of the Champions League after their fans were once again involved in violence. Polish hooligans clashed with Spanish police before Tuesday night's match, injuring 12 people, including three Spanish policemen. 13 Polish fans were arrested. Earlier this season the Polish champions were hammered 5-1 at home by Borussia Dortmund and some fans were involved in violent clashes with police outside the stadium. Legia have already been fined for those incidents and when Real visit on November 2nd, they will yet again be playing in behind closed doors
Yannick Carrasco scored the only goal of the game as Atlético Madrid maintained their 100% record in Champions League Group D with a 1-0 win at Rostov.
The visitors went into the game on the back of a four-game winning streak culminating in a 7-1 thrashing of La Liga rivals Granada on Saturday.
And although they were not able to repeat such a rout against a resolute Rostov defence, Carrasco's 62nd-minute volley from a Juanfran cross proved enough to give Atlético the points.
Sevilla also took a step closer to the Champions League knockout stages as Samir Nasri scored the only goal of a 1-0 win at Dinamo Zagreb.
The Frenchman's deft first-half finish was reward for a dominant performance from the Spaniards on a wet night at the Maksimir Stadium.
Jorge Sampaoli's men could qualify for the next stage when they host Dinamo in a fortnight.
Results:
Wed 19th October
FK Rostov 0 - 1 Atletico Madrid Bayern Munich 4 - 1 PSV Eindhoven Celtic 0 - 2 M'gladbach Barcelona 4 - 0 Manchester City Dynamo Kiev 0 - 2 Benfica Napoli 2 - 3 Besiktas Paris Saint-Germain 3- 0 Basel Arsenal 6 - 0 Ludogorets
Tues 18th October
Dinamo Zagreb 0 - 1 Sevilla Leicester City 1 - 0 FC Copenhagen Club Brugge 1 - 2 FC Porto Sporting Lisbon 1 - 2 Borussia Dortmund Real Madrid 5 - 1 Legia Warsaw CSKA Moscow 1 - 1 Monaco Bayer Leverkusen 0 - 0 Tottenham Hotspur Lyon 0 - 1 Juventus