Premier League title race: How top six is shaping up
Chelsea's Premier League title rivals thought the door had been pushed ajar after a run on 13 straight wins ended at Tottenham and the new harmony under manager Antonio Conte was disturbed by Diego Costa.
The title pacesetters would always be able to recover from a bad result - but how would they cope with the exclusion of their firebrand top scorer after a training ground bust-up and suggestions of interest from China?
Chelsea gave their answer with an impressive 3-0 win at Leicester City that, combined with the weekend's other results, put them firmly back in control of their Premier League destiny.
So, after 21 games and another weekend of significant matches, how are the top six clubs shaping up?
Chelsea - 1st
Form: Won 14 out of past 15.
Upcoming fixtures: 22 January - Hull (home), 31 January - Liverpool (away), 4 February - Arsenal (home).
Conte will have demanded an instant Premier League response from his team after that 2-0 loss at White Hart Lane, which he rightly placed in context by pointing out it was inflicted by a quality side with title aspirations of their own.
The wildcard was provided by the sudden falling out with influential striker Costa that provided an unexpected backdrop to Saturday's events at the King Power Stadium and gave the first hint of dissent in Chelsea and Conte's camp this season.
In the end, the Italian boss was given the opportunity to prove the versatility and flexibility of his squad in Costa's absence as Willian, Eden Hazard and Pedro provided the attacking threat.
In the absence of any suggestion Blues owner Roman Abramovich will bow to pressure to sell in January, the priority now is to get the combustible Spain striker back on side and ensure any unrest does not spread.
If that can be done, then Chelsea can look back at a weekend where their title position was strengthened as they now stand seven points clear.
Verdict: Back on track and clear title favourites.
Tottenham - 2nd
Form: Won past six.
Upcoming fixtures: 21 January - Manchester City (away), 31 January - Sunderland (away), 4 February - Middlesbrough (home).
Mauricio Pochettino's side are a growing force in this title race and the 4-0 demolition of West Bromwich Albion was further evidence of their growing authority.
It was their sixth straight league win since their loss at Manchester United in December - and they have only lost two games out of 21.
Harry Kane is firing on all cylinders, shown by his hat-trick against West Brom, and with Dele Alli scoring seven goals in his past five league games Spurs are starting to look the full package.
They ran out of steam towards the end of last season, but Pochettino is a top-class operator who will surely have learned his lesson and tailored his team's intense style accordingly.
The Argentine will still hope to avoid injuries and there is a real worry over influential defender Jan Vertonghen, who Pochettino fears has suffered a "bad" ankle injury.
Next weekend's game at Manchester City will tell us even more about them.
Verdict: Flew under the radar for a while but now right at the heart of the title race.
Liverpool - 3rd
Form: One defeat in past 19.
Upcoming fixtures: 21 January - Swansea (home), 31 January - Chelsea (home), 4 February - Hull (away).
Liverpool will be disappointed they could not hold on for victory at Manchester United on Sunday, but there is plenty of encouragement to take from their performance.
The disappointment will come because they were within six minutes of securing a win that would not only have inflicted even more damage on United, but also would have sent a strong message to those nearer the top of the table.
It is to the Reds' credit that they came so close to victory despite key men such as Philippe Coutinho still not fit enough to start, Nathaniel Clyne out with a rib injury and Joel Matip sidelined because of confusion surrounding his absence from Cameroon's Africa Cup Of Nations squad.
Manager Jurgen Klopp rightly believes they are still in a strong position but will surely be frustrated that Zlatan Ibrahimovic's late goal means Chelsea stretched their advantage to seven points.
Verdict: Remain title contenders but top four would still be fine achievement.
Arsenal - 4th
Form: Unbeaten in past four.
Upcoming fixtures: 22 January - Burnley (home), 31 January - Watford (home), 4 February - Chelsea (away).
Arsenal's win at Swansea City could not have been more convincing and they have responded well to successive losses at Everton and Manchester City, when they conceded winning positions and showed the vulnerability that has haunted them for seasons.
Even at the Liberty Stadium on Saturday they made a slow start, but it is hard to argue with a 4-0 away win.
Arsenal manager Arsene Wenger wants the Gunners to stay in the title shake-up until the closing stages - and they are certainly doing that so far.
Are they, however, potential Premier League winners? They cannot be ruled out but it is hard to see where they will pick up the points to haul in Chelsea.
Verdict: In the mix as their manager demands, but will a soft centre let them down?
Manchester City - 5th
Form: Two defeats in past three.
Upcoming fixtures: 21 January - Tottenham (home), 1 February - West Ham (away), 5 February - Swansea (home).
Manager Pep Guardiola effectively wrote off Manchester City's title challenge after they were giving a thorough working over and beaten 4-0 at Everton.
City now face a fight to finish in the top four with a side seemingly physically weak, riddled with defensive frailty and a goalkeeper in Claudio Bravo who hardly ever seems to save a shot. Failure to make next season's Champions League would represent a catastrophe in the Spaniard's first season.
And this is Guardiola's responsibility after he shipped out England keeper Joe Hart on loan to Torino. Out of the past 22 shots Bravo has faced, 14 have been goals.
Only five teams have a lower haul than City's tally of four clean sheets and they have conceded from the first shot they have faced in four of their past seven games.
The problems are there for all to see, although Guardiola has so far done little to correct the faults.
City have suffered two damaging defeats on Merseyside in recent weeks - and do not look like a side who have the slightest chance of making up a 10-point deficit on Chelsea.
Verdict: Forget the title. Manchester City are in a top-four fight now.
Manchester United - 6th
Form: Unbeaten in past 12.
Upcoming fixtures: 21 January - Stoke (away), 1 February - Hull (home), 5 February - Leicester (away).
Manchester United are showing definite signs of improvement under manager Jose Mourinho, but like neighbours City their fight is now for the top four rather than the title.
They could have closed to within two points of Liverpool with victory at Old Trafford on Sunday, but 12 points is surely an impossible gap to breach between United and Chelsea.
United have drawn seven league games - including five at home - and the simple fact is they have squandered too many points to make up the deficit.
Mourinho is definitely moving United forward, but not fast enough to make them title contenders this season.
Verdict: Top four should be the target. The title is now out of reach.