London - Manchester United manager Jose Mourinho returns to his former home on Saturday seeking to stop the rot against a high-flying Chelsea team playing with a smile on their faces under Maurizio Sarri.
That rousing revival kept the man who won three Premier League titles at Chelsea in a job for now.
But a far more demanding run of fixtures, including two matches against Juventus and a trip to Premier League champions Manchester City, will determine whether that victory was a turning point or a false dawn.
United travel to Stamford Bridge already seven points adrift of Chelsea, who are level on 20 points at the top of the Premier League with City and Liverpool.
Mourinho's season has been blighted by confrontations with key players and an inability, or refusal, to play the brand of attacking football United fans became accustomed to during the glory years of Alex Ferguson's 27-year tenure.
After missing out on City boss Pep Guardiola and Liverpool manager Jurgen Klopp in the years since Ferguson's retirement in 2013, United may also come to regret not chasing Sarri when the Italian was on the market in the summer.
Even during his successful periods in two spells at Chelsea, Mourinho was an arch-pragmatist. Despite his clashes with Sarri's predecessor at Stamford Bridge, Antonio Conte, the two had more in common than they would probably like to admit when it came to tactics.
Sarri's style could not be more different. The Italian has put the smile back on faces at Chelsea with an attractive brand of football that has also produced results.
"There are moments when the grand spectacle of it all convinces you to put aside any regrets, even if you concede at the last minute or five minutes into stoppages," Sarri told Italian newspaper Corriere dello Sport, reliving the challenge of facing Klopp as Liverpool snatched a 1-1 draw with a late equaliser last month.
"That was an extraordinary show. Just 10 minutes earlier, I saw Klopp looking at me with the game going on. I asked: 'Why are you smiling?' He replied: 'Aren't you having fun?'
"I said: 'So much' and he added 'me too'. He was losing at the time. Even after the equaliser, remembering that moment, we hugged like two old friends."
Chelsea's players have flourished under Sarri, none more so than the Premier League's top goalscorer Eden Hazard.
"I like this type of game. It's completely different than Conte or Mourinho before," said the Belgian, who has eight goals already this season. "We have more ball so for me it's not bad."
Sarri has challenged Hazard to score 40 goals this season, adding: "It is easy to stimulate Hazard - as long as you let him have fun."
How the likes of Paul Pogba, Alexis Sanchez and Anthony Martial must wish they had the same creative freedom at Old Trafford.
All three were instrumental in United's fightback against Newcastle when, with nothing to lose, Mourinho threw caution to the wind.
In three previous visits back to Stamford Bridge as United boss, Mourinho's conservative set-up has delivered three defeats without a single goal.
The time has come, like Sarri, to embrace the "spectacle" if he is to see out a treacherous three weeks ahead.