Manchester City pulled five points clear at the top of the Premier League table after Huddersfield Town's excellent 2-1 win over Manchester United, handing Pep Guardiola a crucial advantage – and suggesting his attacking tactics are even better defensively than Jose Mourinho's.
Everton and West Ham United continued to struggle, suggesting they will soon be switching managers, while West Brom were sucked into trouble and Tottenham Hotspur showed great maturity in their defeat of Liverpool.
Here are three things we learnt from the weekend action:
1) Ozil & Sanchez will destroy any team naive enough to play just on defensive midfielder
This was only the second time this season that Mesut Ozil and Alexis Sanchez have started together in that dual number ten role, and it was easy to see why Arsenal have struggled for fluency without them. Ozil set a new record for the 2017/18 season by making eight key passes on a day in which Ronald Koeman's midfield selection invited danger.
Idrissa Gueye was hugely overworked in defensive midfield (hence the desperate lunges that eventually saw him dismissed), as both Nikola Vlasic and Gylfi Sigurdsson sat higher up the pitch. Not only was Gueye left isolated from a tactical perspective at the tip of a V-shaped midfield, but Everton's poor form also contributed to the Senegal international's problems.
Time and again the Everton midfield pressed only to find the centre-backs had dropped off, opening a huge pocket of space in the number ten zone for Ozil and Sanchez to exploit. It was precisely the sort of defensive sloppiness that often appears when confidence, and thus team cohesion, is low. Ozil was bound to flourish in a match like this one; Everton won just eight of their 19 attempted tackles.
2) Evolving Spurs teach Liverpool how to defend against quick attackers
Mauricio Pochettino's team have developed a brand new tactical approach this season for games against high-line counter-pressing teams. As in the 3-1 victory over Borussia Dortmund and the 1-1 draw with Real Madrid at the Bernabeu, Spurs utilised a counter-attacking 3-5-2 formation that relied on patient – and deep – defending. It exemplified the exact qualities that Jurgen Klopp's one-note team lack.
Spurs did not press high, as Klopp had anticipated, but instead allowed the visitors to push forward in numbers. This meant Mohamed Salah had very little space to run into and that Liverpool were vulnerable to incisive counters, led on this occasion by Harry Kane and Heung-Min Son. Together, these two cut through a shaky Liverpool defence to score those decisive early goals.
The patience and diligence of Spurs' tactics was a stark reminder of Liverpool's inflexibility. Klopp should have used a deeper line on that big Wembley pitch, forcing the hosts to have long spells of possession – which, counter-intuitively, would have made Pochettino's team more nervous. Instead, Spurs were allowed to play as if the away side at a ground that doesn't yet feel like home.
3) Directionless West Bromwich Albion suggest Tony Pulis is in a relegation battle
A run of seven league matches without a win has left West Brom just two points outside the bottom three, quietly sucking them into a relegation battle after those back-to-back 1-0 wins at the beginning of the campaign. Judging by the tactical deficiencies on display at Southampton on Saturday, Tony Pulis's side are set for a tough year.
The main problem for the Baggies is that their midfield players are too similar. Gareth Barry, Jake Livermore, and Grzegorz Krychowiakare all slow, unwilling to move forward, and largely play sideways passes. Consequently their attackers become isolated; Salomon Rondon didn't manage a shot on goal, while wingers Nacer Chadli and Jay Rodriguez failed to create a single chance between them.
Unless Pulis allows his team to play a more expansive game, West Brom might be unable to halt the slide. With Spurs, Man City, and Chelsea to play in the next four weeks things aren't going to get any easier.
Best of the Week – Huddersfield's hunger to win the tactical battle
Jose Mourinho correctly identified that "the best team won" in his post-match comments, and any neutral watching can only have reached the same conclusion. Huddersfield were more aggressive, more compressed in their overall shape, and better in the tackle than their lacklustre opponents.
David Wagner's defensive approach can be overly cautious at this level, but Huddersfield were surprisingly bold in their pressing on Saturday, winning 27 tackles – more than twice as many as Manchester United. More home performances like this and Huddersfield won't have to worry about a relegation battle.
Worst of the Week – West Ham United
The most damning thing about West Ham matches of late is the total absence of a coherent plan. It is difficult to criticise Slaven Bilic's tactics because there didn't appear to be any; West Ham slumped to a deserved 3-0 defeat, having struggled to play with any fluency against Brighton's sturdy defence.
Pablo Zabaleta was the only player showing creativity for the hosts, who simply don't have enough invention in attack to outthink anyone willing to concede possession and territory. It is a lack of ideas, not the results, which suggest Bilic's time at the club is over.