Chelsea suffered their worst Premier League collapse of the 2000s in their shock 2-1 home loss to Fulham at Stamford Bridge on Boxing Day.
Victory for Enzo Maresca's team in the West London derby would have cut the gap to leaders Liverpool to just one point, albeit having played two more games than the Reds.
Chelsea's quest for three points against their near neighbours kicked off on the right foot, as Cole Palmer guided home an exquisite side-footed opener after evading a couple of challenges.
The England international broke a Chelsea goalscoring record with his sublime strike at Stamford Bridge, but his 26th Premier League goal of 2024 would not be a precursor for a dominant derby win.
A late leveller from Harry Wilson preceded a last-gasp winner from Rodrigo Muniz, who sent the away end into pandemonium in the fifth minute of added time as Fulham won a league game away to Chelsea for the first time in 45 years.
Chelsea condemned to biggest Premier League collapse since 1999
© Imago
Chelsea were a goal to the good until Wilson struck with eight minutes of normal time remaining, and Thursday's loss marked the first time since October 1999 that they have lost a Premier League game where they were leading up to the 82nd minute.
On that occasion, the Blues were coincidentally also at home to another London rival in the shape of Arsene Wenger's Arsenal, taking a 2-0 lead inside the hour mark thanks to Tore Andre Flo and Dan Petrescu.
However, Kanu cut the deficit in half in the 75th minute, before drawing Arsenal level in the 83rd and completing a stunning hat-trick on the 90-minute mark against Gianluca Vialli's Chelsea.
An absent attacker stole the pre-game headlines at Stamford Bridge on Boxing Day, as Noni Madueke was left out of the squad entirely after being given just 14 minutes in the goalless draw with Everton at the weekend.
Instead, Maresca selected Tyrique George and Marc Guiu to fill the empty spots on the bench, as well as calling up third-choice goalkeeper Marcus Bettinelli alongside number two Filip Jorgensen.
Maresca: 'Madueke absence was a technical decision'
© Imago
Explaining Madueke's snub, Maresca simply stated that the winger's absence was a 'technical decision', although he has not been shy to criticise the England international in the past.
Madueke started 11 Premier League games on the bounce before being demoted for the 3-0 win over Aston Villa in early December, although the 22-year-old still came off the bench to register an assist that day.
On that day, Maresca openly admitted that Madueke's attitude to training was poor, and he is seemingly fighting an uphill battle to return to the fold for Monday's trip to Ipswich Town.
Chelsea' loss coupled with Liverpool's 3-1 win over Leicester City later in the day saw the Blues fall seven points behind the Reds in the Premier League table, and they will also be leapfrogged by Arsenal if the Gunners beat Ipswich Town on Friday.
Ben Knapton
