Manchester United have a golden opportunity to haul themselves into the Premier League title race at the expense of bitter rivals Liverpool this weekend.
While all is sweetness and light for the moment with United and manager Jose Mourinho, the storm clouds may be gathering over his former side Chelsea, who had soared to the top of the table on the back of a 13-match winning run.
Defeat last time out to Spurs brought that to an end but hopes of bouncing back against ailing champions Leicester have taken a serious hit after leading scorer Diego Costa was dropped for an apparent bust-up with the coaching staff over his fitness.
United go into the Old Trafford showdown in fine fettle after beating Hull in the League Cup semi-final first leg in midweek to extend their winning streak in all competitions to nine matches.
Mourinho's sixth-placed side still trail Chelsea by 10 points and lag five behind second-placed Liverpool.
But victory on Sunday would be a significant statement of intent and Mourinho promised a far more attacking performance than United delivered in a dour 0-0 draw against Liverpool at Anfield in October.
"You know, at that time I had less time of working together with my players," Mourinho said.
"Now I have a little bit more, we know each other better, we have a certain way of thinking football, we have a certain way to play football,"
"We don't just have good performances, we have also the happiness of the good results," Mourinho said.
In contrast to United, Liverpool – after emerging as title contenders thanks to a four-match winning run in December – have suffered a dip.
A draw at Sunderland in the league was followed by an FA Cup stalemate against fourth-tier Plymouth and a 1-0 defeat in the League Cup semi-final first leg at Southampton.
Manager Jurgen Klopp will hope the return against Southampton of Brazil forward Philippe Coutinho after seven weeks out with an ankle injury provides a timely boost for his team.
"We will try everything we need to make the difference," Klopp said.
"Everyone who wants to see a real fight, then yes, watch it. It will be 100 per cent from our side," he said.
By the time Liverpool kick off at Old Trafford they could be eight points behind Chelsea, who face struggling champions Leicester at the King Power Stadium 24 hours earlier.
"I think the Leicester game is very important. It's important for us to restart winning," Chelsea manager Antonio Conte said before the Costa bust-up was revealed.
On the field, midfielder N'Golo Kante will make a first appearance at Leicester since his £30 million pre-season transfer.
Kante was the driving force behind Leicester's incredible title triumph and his absence has been felt as the Foxes have slumped to within six points of the relegation zone.
Leicester boss Claudio Ranieri called on the club's fans to salute Kante, but he hopes his side can make it an unhappy return.
"I hope our fans give to Kante a warm welcome as he was our champion. It's important to remember what he gave to us," Ranieri said.
"We respect Chelsea a lot but we are ready to fight and ready to try to win," he said.
Third-placed Tottenham can extend their winning run in the league to six matches when they host West Bromwich Albion, but boss Mauricio Pochettino isn't getting carried away by that impressive success against Chelsea.
"Today it's about maturity and learning from this period. It doesn't mean that we will win every game," he said.
"It's important to show that maturity we did against Chelsea, that is important for trying to be more realistic and fighting for a bigger objective," Pochettino said.
Manchester City, in fourth, look to maintain the momentum from their FA Cup thrashing of West Ham when they travel to Everton, while fifth-placed Arsenal, eight points behind Chelsea, can't afford a slip at second-bottom Swansea.
It will be an emotional day at Vicarage Road as Watford pay their respects to former manager Graham Taylor following his death on Thursday aged 72.
Taylor, who suffered a suspected heart attack, led Watford into the top flight twice in two spells lasting a combined 15 years and the club plan a minute's applause and other tributes before their home match against Middlesbrough.
Fixtures (20:30 IST unless stated)
Burnley v Southampton, Hull v Bournemouth, Leicester v Chelsea (23:00 IST), Sunderland v Stoke, Swansea v Arsenal, Tottenham v West Brom (18:00 IST), Watford v Middlesbrough, West Ham v Crystal Palace
Everton v Manchester City (19:00 GMT), Manchester United v Liverpool (21:30 GMT)
Updated Date: Jan 14, 2017 10:50 AM