The Premier League title race is surely over after Manchester City out-thought and out-classed their rivals Manchester United to open an 11-point gap at the top. The game was final proof that Jose Mourinho simply isn't as good a coach as his rival Pep Guardiola.
Elsewhere Chelsea look closer than ever to a collapse following their jaded display away at West Ham United on a weekend when only two of the top six teams recorded three points. Tottenham Hotspur's 5-1 victory over Stoke City suddenly lifts them back into contention for second spot.
Here are three things we learnt from the weekend action:
1) Opposing tactics in Manchester derby prove Guardiola is streets ahead of his rival
For the first time since they pitched up in Manchester, this was a derby defined by the polar opposite tactical philosophies of the two great rivals; Pep Guardiola's side were fluid in possession and brave in their creativity, while Jose Mourinho's team sat deep and launched long balls forward. Manchester City may have won thanks to two Romelu Lukaku mistakes, but this was a match that proved United's manager is no longer on the same level as Pep.
City's performance was a reminder of Guardiola's brilliant individual coaching, his tactical clarity in attack, and the malleability of his squad. The defining tactical feature was the position swapping of his front three as Gabriel Jesus frequently confused the United defence by vacating the number nine spot while Raheem Sterling caused havoc by floating into the centre time and again. Sterling's intelligent movement showed just how much he has developed under Guardiola, and allowed his side to dominate midfield thanks to their spare man in central areas.
By contrast, United were flat and directionless. Not a single player has improved under Mourinho's tutelage - a damning indictment of the chasm between the two coaches. One side showed courage and strength, the other betrayed their manager's hostility and caginess; it is difficult to accept these two rivals are on the same planet any more.
2) Jaded attacking patterns hint at exhaustion for both Chelsea and Conte
Antonio Conte's petulance over the past few months has suggested he is ready to walk away from Chelsea. The timidity and weariness of their performance at West Ham United suggests his attitude is rubbing off on the players; there is no way the Italian will remain beyond the end of the season, but at this rate he might just walk away much sooner.
The tiredness wasn't just physical, although by the start of the second half most of the Chelsea players looked to be suffering from a lack of fitness (hinting at the lack of depth in Conte's squad; nine players have started 10 or more of their 15 league games this season). Creatively the team seemed bereft of ideas as their jaded minds struggled to understand how to break down a relatively simple David Moyes defence.
Chelsea consistently attacked through the centre of the pitch, first because their only playmaker, Eden Hazard, didn't move from the number ten zone, and then after Pedro was introduced because both creators refused to shift wide. It was a bizarrely narrow and one-dimensional approach that West Ham, packing the middle with bodies and sitting deep, nullified all too easily. An emotionally exhausted Conte and Chelsea look out of ideas.
3) Allardyce's negativity suggests he doesn't yet know how to balance his Everton side
Everton were very lucky to earn a point at Anfield after a soft penalty was awarded and Liverpool failed to convert their superiority into goals. Sam Allardyce's side did well defensively to frustrate the hosts – he won't have minded conceding possession – but Everton were completely boxed in, largely because of the manager's poor team selection.
Playing in a flat 4-4-2, Everton were relying on long balls from Gylfi Sigurdsson and Wayne Rooney towards the two pacey strikers, and although this eventually led to the penalty equaliser it was by and large an unsuccessful tactic. Dominic Calvert-Lewin and Omar Niasse were constantly isolated because neither Rooney nor Sigurdsson had the pace or mobility to get up alongside them and offer support. Likewise, Tom Davies was overworked in the centre, meaning he was trapped inside his own third.
It was a formation that didn't suit the team going forward, although they looked slightly better when Aaron Lennon came on for Niasse and the Toffees went into a 4-2-3-1. Allardyce's defensive coaching is beginning to take effect – but he is a long way from working out how to balance this chaotically lopsided squad in attack.
Best of the Week – Dembele controlling midfield as Spurs dominate Stoke
Stoke City's dreadful defending certainly made it easier for Christian Eriksen and Son Heung-Min to run riot at Wembley on Saturday, but behind much of their creative work was Mousa Dembele, who looks back on form following his ankle injury.
Dembele had more touches (118), more passes (105), and more dribbles (3) than any other player on the pitch, controlling the tempo of the game with his calm distribution from the base of midfield. Tottenham have badly missed his authority in the middle.
Worst of the Week – Romelu Lukaku
United were poor in all areas but this match could still have ended in a typically scruffy Mourinho win had Lukaku shown up. His touch was dreadful, his movement non-existent, and his finishing wretched. Not only did he have three clear cut opportunities to score, he also consistently caused United attacks to break down.
To add insult to injury it was Lukaku's two mistakes that led directly to the City goals. This was surely the worst performance of the Belgian's career, and at the worst possible moment. Criticism regarding his suitability for a top club – and ability to show psychological strength in the biggest matches – is not going away.