Chelsea's simple win over Swansea City has put the final nail in the coffin for Manchester City, who may have held a glimmer of hope following the Premier League leaders' draw at Burnley a fortnight ago.
With Manchester United, City and Liverpool all not featuring this weekend, focus shifted to the Premier League's relegation battle, while Tottenham Hotspur slightly kept pace with the Blues but still remain 10 points behind after their dominant 4-0 victory over Stoke City.
Crystal Palace's 1-0 win over Middlesbrough might just be the most important result of the season for both clubs, while a point each for Hull City and Burnley has piled the pressure on manager-less Leicester City before their game against Liverpool on Monday night.
Here's what we learned from the weekend's league action:
1) Lock-picker Fabregas proves he is an invaluable – and irreplaceable – member of the Chelsea squad
Cesc Fabregas has endured a difficult season under Antonio Conte, but his crucial impact on Saturday (one goal, one assist) proved that he is a uniquely elegant, lock-picking option in midfield.
Against deep-lying teams such as Swansea, he is exactly the kind of player that is required; Conte needs to keep him happy between now and the end of the season, because he is an irreplaceable asset in the modern game.
Fabregas had more touches (127) and made more key passes (five) than any other player on the pitch, and – perhaps more impressively – was positionally disciplined throughout; Chelsea's opener followed a good tackle from the Spaniard in the centre of the park.
At times this season Chelsea's double pivote of Nemanja Matic and N'Golo Kante has looked too flat (such as in their series of 1-0 wins against Palace, Boro, and West Bromwich Albion), making Fabregas an essential member of the squad as an impact player.
His goals and assists have earned Chelsea at least seven points this season, and set up Diego Costa's crucial 59th-minute equaliser at the Etihad in December.
Without Fabregas, Man City would most likely be above Chelsea, or at least closer, in the table. The lesson from Saturday is this: give Fabregas more game time or risk losing a player whose vision and ingenuity are irreplaceable in the current market.
2) Rampant Alli & Eriksen provide conclusive evidence that Spurs must permanently convert to 3-4-2-1
Mauricio Pochettino's relationship with the Conte-mimicking 3-4-2-1 is difficult to comprehend.
After drawing 2-2 away at City and defeating Chelsea 2-0 at White Hart Lane amid a sequence of good results using this formation, Tottenham Hotspur bizarrely reverted back to 4-2-3-1 – with mixed results.
Sunday's 4-0 destruction of Stoke was definitive evidence that their long-term future depends upon using a 3-4-2-1.
The strength of Spurs mirror exactly those of Chelsea. They possess three strong centre-backs capable of stepping out with the ball (Eric Dier can, like David Luiz, shuffle into a defensive midfield position when necessary); their attack-minded full-backs work better when given licence to roam as wing-backs; in Mousa Dembele and Victor Wanyama they have Kante/Matic style solidity; and Dele Alli and Christian Eriksen are best utilised as dual number tens.
Eriksen completed a remarkable seven key passes against Stoke, partly because Alli was so distracting in a similar zone and partly because Kyle Walker and Ben Davies stretched the pitch so consistently as wing-backs.
Between them, Alli and Eriksen had 152 touches of the ball and scored or assisted three of the four Spurs goals, among Harry Kane's hat-trick.
It is a lesson Pochettino should have learnt by now, and one he can surely no longer ignore: 4-2-3-1 is the formation that maximises Tottenham's potential.
3) Van Aanholt's brave attacking movement accentuates Middlesbrough's lack of courage – and suggests Karanka's team will go down
Premier League survival comes down to the finest of margins.
Patrick van Aanholt's venture forward, and driven shot into the corner of the net, handed Sam Allardyce his first home win to lift Crystal Palace out of the bottom three. It could be the very gamble that ultimately keeps them in the division.
Middlesbrough have scored just three league goals in 2017 and appear alarmingly cautious in their tactical approach, a fault that was emphasised by van Aanholt's aggressive forward thinking. The Dutch left-back managed as many shots on goal as Alvaro Negredo and Rudy Gestede combined.
Big Sam wrote in his programme notes that Palace needed to learn how to grind out draws, but his instruction to respect the conservative approach was largely ignored by his new signing.
Middlesbrough desperately need someone to take similar risks, or relegation back to the Championship is a certainty.
Best of the Week – Gareth McAuley
West Brom's 37-year-old centre-back is having an outstanding season.
His sixth goal of the campaign was enough to hand the Baggies another three points on Saturday, and on his 500th career game no less.
The Northern Irishman deserves recognition simply for becoming the archetypal Tony Pulis player; strong, consistent, and dangerous from set-pieces.
McAuley hit the woodwork from another set-piece later in the game and, just moments after giving his team the lead, blocked a shot from Jack Wilshere that appeared to be heading in. It was the kind of heroic performance that is emblematic of West Brom's quietly outstanding 2016/17 campaign.
Worst of the Week – Sunderland's midfield
Sunderland's performance at Everton, though not particularly bad, exemplified precisely why they are going down.
Darron Gibson and Seb Larsson made just one interception between them and averaged a 65% pass success rate; such statistics will inevitably lead to defeat against the likes of Ross Barkley and Idrissa Gueye.
Blame lies with David Moyes for some drab, unimaginative purchases over the summer.
Didier Ndong aside, the former Everton manager has assembled a team of Championship-standard players who simply don't have the quality to play at this level.