AFP Sport rounds up some of the main talking points from the action across the continent:
Wind of change?
There is a school of thought that this season represents the best chance in a long time for a surprise winner in some of Europe's biggest leagues, given the disruption caused to the calendar by the coronavirus pandemic.
Coming into this season, Juventus had won nine titles in a row in Italy, Bayern Munich had won eight on the bounce in Germany, and Paris Saint-Germain had won seven of the last eight Ligue 1 crowns, while it takes an exceptional year for neither Barcelona nor Real Madrid to win La Liga.
However, more than halfway through October, and while Everton lead the Premier League, it is Real Sociedad who sit top in Spain, while RB Leipzig lead the way in Germany, AC Milan are first in Serie A and Lille top Ligue 1.
Maybe a wind of change is sweeping through European football? It is possible, although there is still ample time for the superclubs to reclaim the positions they feel are rightfully theirs.
Mediocre Madrid and Barca
Barca host Madrid in the first Clasico of the season on Saturday, but the fixture that was for a long time the most glamorous in Europe has lost much of its lustre.
Madrid, the reigning champions, went down to an abject 1-0 home defeat against newly-promoted Cadiz at the weekend. With nine starters who have been at the club since at least 2014, they appear in desperate need of freshening up.
Barcelona, meanwhile, went down 1-0 at Getafe. For all the talk of revolution at the Camp Nou, this is still much the same team as that humiliated by Bayern in the Champions League in August, and new coach Ronald Koeman has a huge job on his hands.
Milan on the way back?
AC Milan have spent most of the last decade in the doldrums but it is beginning to look like they could offer a genuine challenge to Juventus in Serie A this season after the Rossoneri kept up their perfect start by beating Inter in the "Derby della Madonnina".
Zlatan Ibrahimovic, who is now 39, scored both goals for Milan in a 2-1 win at San Siro as they beat their great rivals in Serie A for the first time since January 2016.
Stefano Pioli's side are two points ahead of Sassuolo at the top, as well as four points ahead of Juventus and five above Inter.
Ibrahimovic was making his comeback after a spell quarantining due to Covid-19. "They locked the wrong animal at home for two weeks," he said.
The Swede was Milan's top scorer when they last won the Scudetto in 2011. They have not finished higher than fifth in Serie A since 2013 and not been in the Champions League since 2013/14. Are they now on the way back for real?
Ajax warm up for Liverpool
Ajax warmed up for the start of their Champions League campaign and Wednesday's meeting with Liverpool by winning big in the Eredivisie.
They beat Heerenveen 5-1 in Amsterdam, and while some of the big stars of their run to the semi-finals in Europe in 2018/19 have since moved on, their line-up still featured six players who had a big contribution in that run.
One was Dusan Tadic who scored twice against Heerenveen, including a penalty. Another penalty was converted by Davy Klaassen who recently returned to Ajax after spells at Everton and Werder Bremen.
Erik ten Hag's team are second in the Dutch table, a point behind PSV Eindhoven.
Covid halts Czech season
While the Champions League begins this week with UEFA having recently given the green light for clubs to open stadiums up to 30 percent of capacity, the continuing rise in Covid-19 cases across Europe increases the threat of more disruption for the sport.
The Czech campaign has been suspended for at least two weeks, and with just six rounds of games played, because of the health crisis.
Despite that two Czech sides -- Sparta Prague and Slovan Liberec -- are due to play at home in the Europa League this week.
Other European leagues will be hoping the same disruption does not await them.