Manchester City's eight-point lead at the top of the Premier League table remains intact but a confident performance from their cross city rivals, led by the returning Paul Pogba, has increased the pressure on Pep Guardiola's men on a weekend of resounding victories for the big teams.
Chelsea's 4-0 win at West Bromwich Albion has increased the pressure on Tony Pulis, while David Moyes got off to a losing start thanks to a poor team selection at Vicarage Road. It is a long uphill battle from here for the new West Ham United manager.
Here are three things we learnt from the weekend action:
1) Another tactical master class from Silva shows up Moyes's glaring team selection errors
A typically energetic performance from Watford, whose pass-and-move patterns are remarkably astute under Marco Silva, was enough to out-battle West Ham United on David Moyes's debut, and although the visitors created several good opportunities they cannot argue with the result. Moyes's team selection ultimately let them down.
Perhaps keen not to conform to the perception he is overly negative Moyes picked Manuel Lanzini and Marko Arnautovic as wingers in a 4-3-3 formation, which meant both Hammers full-backs received very little defensive support. Neither of these two flair players work hard enough to function in this system, with Arnautovic in particular an odd choice on the right.
Watford's intelligent new system clearly caught Moyes by surprise. Silva played Richarlison and Will Hughes as inside forwards in a 3-4-2-1 (the Antonio Conte formation of 2016/17) with the Brazilian consistently pulling out to the left with late runs. This made it tough for Pablo Zabaleta to keep him in sight, and with Arnautovic failing to track back Zabaleta simply had too much to do – particularly with left wing-back Marvin Zeegler in excellent form. The tempo was set with constant attacks down the left in the first half, eventually leading directly to the opening goal.
2) Hazard's new second-striker role shows Conte's tactics keep evolving
Not unlike Dele Alli at Tottenham Hotspur, Eden Hazard is enjoying a new role in 2017/18 - that of the second-striker who starts behind Alvaro Morata but frequently makes late runs ahead of him. Conte hinted at the end of the 2016/17 season that his 3-4-2-1 formation would soon be found out and so must evolve to stay ahead of the pack, and while the Italian has endured a difficult start to the new season he has been true to his word.
Chelsea now line up in a 3-5-1-1 formation, which, with a third body in the centre, allows them to maintain greater control over the midfield now that opponents are sitting deeper to prevent the Blues from springing counter-attacks. It also means Hazard stays more central than he used to and can begin to play more like a centre-forward.
It was traditional number ten play that led to Hazard's shot for the first Chelsea goal, but the Belgian's two goals came via through-balls from Cesc Fabregas that spotted Hazard's runs on the shoulder of the last defender.
3) Spurs' lacklustre midfield highlights fitness concerns – and the need for new recruits in January
Arsenal's tenacity in collectively pressing Spurs was a big surprise, but even bigger was Tottenham's inability to play with their usual swagger, suggesting fitness problems are developing for Mauricio Pochettino's side. More alarmingly, the flatness of their midfield teaches us that the Argentine needs to sign another central midfielder in January.
Moussa Dembele, Harry Kane, and Christian Eriksen all looked tired, but more importantly the entire midfield looked incapable of the usual high-tempo movement that is required to build out from the back – which made it easy for Arsenal to keep the visitors under pressure.Moussa Sissoko was the least effective in the team while substitute Harry Winks struggled following his recent injury.
This match indicates Spurs will struggle over Christmas and fitness will start to become an issue as the matches pile up, meaning another addition in central midfield (to replace Sissoko) is a necessity. Spurs have had a tough fixture list recently, but one goal in their last three league matches speaks volumes.
Best of the Week – Paul Pogba
Based on xG statistics Manchester United should have lost each of their last four league matches before the 4-1 victory over Newcastle United on Saturday evening. Watching Paul Pogba swagger across the Old Trafford turf, it is easy to see what they've been missing.
The Frenchman was outstanding, raising the tempo with his quick vertical passing and thus setting a new tone for a team who so often seem sluggish on home soil. His goal and assist were richly deserved, and the way in which he celebrated with his friend Romelu Lukaku suggests United can look forward to a string of victories in the coming weeks.
Worst of the Week - Southampton's defending
From the very first whistle Southampton didn't seem up to the task of defending against Liverpool's electric front four. Sadio Mane, Philippe Coutinho, Roberto Firmino, and Mohamed Salah tore their opponents to shreds at Anfield, partly because the visitors couldn't track Coutinho's runs from a false-eight position but partly because they just weren't strong enough.
The entire Saints midfield made just three interceptions between them in the match, failing to adequately press on the edge of the area (leading to the first and third goals) or keep a compressed defensive shape (leading to the second goal).