In between two international breaks where players could pick up injuries, and with the Champions League and Europa League under way, this is a crucial period of the season.
Squads are already under pressure, facing fixture pile-ups and having to rotate to cope. There's not much let up between now and Christmas, so if you start to stumble, you might not stop for a while.
It certainly doesn't look that way for Barcelona - six straight wins in La Liga, or 11 if you go back to the end of last season. Neymar and Lionel Messi are both playing along happily, there are no real signs of weakness or complacency, and the transition to new coach Gerardo Martino seems to have gone swimmingly.
Having done their key bit of business late in the transfer window, Real Madrid need to make sure their latest signing settles in just as quickly. A goal on debut will certainly have helped Gareth Bale, but the result from that game (2-2 at Villarreal) means Real are already playing catch-up.
It won't be lost on Carlo Ancelotti that it's not just one team ahead of his, but two. Atletico Madrid were lightning-quick out of the blocks, matching Barca stride for stride, and they don't seem to be missing Radamel Falcao too much.
Diego Costa signed a new contract and is beginning to be seen as prolific rather than problematic, after his confrontations and controversies of last season.
Ahead of this weekend's Madrid derby, Real will point to Atletico winning eight of their first nine league games last season and fading in February. But then Diego Simeone's side edged their most recent meeting (last season's Copa del Rey final), so it's all set up for a enthralling battle at the Bernabeu.
Among the surprises are Villarreal, unbeaten on their return to Spain's top division, but also Sevilla. Yes, they did lose Negredo, Navas, Medel, Kondogbia and Luis Alberto in the summer, but it has taken a while for their replacements to start gelling.
Their first league win of the season arrived only on Wednesday, 4-1 at home to Rayo Vallecano, which will have come as a huge relief to Unai Emery.
Over in Germany, there's no reason for Bayern Munich or Borussia Dortmund to be unduly worried.
Bayern suffered a minor hiccup by drawing at Freiburg, while we saw the fiery side of Dortmund coach Jurgen Klopp during their Champions League defeat away to Napoli. To his credit, he did account and apologise for his outburst at the fourth official pretty quickly.
Domestically, both sides are still unbeaten in the Bundesliga, and the two giving chase face each other this weekend in Bayer Leverkusen and Hannover 96.
Leverkusen's only domestic defeat so far was at Schalke, and after three away games they now have three at home, where they've won their last six.
Hannover have an extremely cosmopolitan squad, with hardly any Germans featuring in the back four or up front - in fact, head coach Mirko Slomka picked players of nine different nationalities in his starting line-up for their last league match, a 2-1 victory over Augsburg, with one more available on the bench.
But another manager is out of a job after a disappointing start: Hamburg's Thorsten Fink could only manage one win from his opening six games, so he's been replaced by the man who guided the Netherlands to the 2010 World Cup final, Bert van Marwijk.
You won't be shocked to see Monaco and Paris Saint-Germain occupying the top two places in Ligue 1, both unbeaten, and their South American star strikers are beginning to pay back their hefty transfer fees: seven goals for Colombia's Radamel Falcao, and four in all competitions for Edinson Cavani of Uruguay.
Overall for both these big spenders, it's so far so good, but a key factor will be how PSG handle their Champions League campaign, whilst Monaco don't have any European distractions to speak of.
Lille have been the most impressive of the chasing pack, especially with their tight defence which has seen them keep four clean sheets in five games, although that will be tested at Lyon this weekend. Bordeaux have been the biggest disappointment so far, with just one win in seven games for last year's French Cup winners.
If that's a compelling picture, then Italy is even more so. In short, it's the sides with new managers who are excelling. Rudy Garcia's Roma have been victorious in all five Serie A games (including one against bitter rivals Lazio), and they are two points clear of Inter Milan, Napoli - now with Rafael Benitez in charge - and Juventus.
Antonio Conte won't be too concerned at this stage, although it does look like Juve may face more of a fight than expected to retain their Scudetto, and they'll certainly get a contest this weekend with a Turin derby.
Fiorentina started well too, but the absence of Mario Gomez will be keenly felt; he could be out until December with knee ligament damage.
It's important to give Inter their due, having defeated the fancied Florence side on Thursday. After a mid-table finish last season, another new boss Walter Mazzarri has done well to impose his work ethic on the squad, and hasn't let anyone get distracted by persistent talk of a takeover on the blue-and-black side of the San Siro.
But on the red-and-black side, Massimiliano Allegri may not last much longer. Five points from as many games just isn't good enough for Milan or their demanding supporters, especially as they needed late goals to salvage draws at Torino and struggling Bologna.
Although he was given the chance to turn things around after a similarly poor start to the last campaign, Allegri may not be so fortunate this time around.
All four leagues have their elements of intrigue, and the plot will thicken in the next month or so, as long as the challengers can keep up with the favourites and steer clear of losing their top players for whatever reason.