Chelsea missed a chance to capitalize on Liverpool’s slip in the race for UEFA Champions League qualification, falling 3-0 to Everton FC on Saturday to remain outside the top five.
Champions Liverpool had slipped to a 2-1 defeat at Brighton in the early kick-off – their 10th loss of a dismal Premier League title defense.
But Chelsea's thumping reverse at the Hill Dickinson Stadium gives renewed hope to a clutch of clubs below them, including Everton themselves, Brentford and Fulham, who beat relegation-bound Burnley 3-1.
The top five teams in the Premier League are almost guaranteed to play Champions League football next season due to the strong showing of English clubs in Europe.
Arsenal are hot favorites to land the Premier League title for the first time since 2004, with second-placed Manchester City well clear of city rivals Manchester United.
United, who drew 2-2 at Bournemouth on Friday, are four points ahead of fourth-placed Aston Villa, who host struggling West Ham on Sunday.
Liverpool arrived on the sunny south coast after completing a morale-boosting 4-1 aggregate win over Galatasaray at Anfield in midweek to reach the Champions League quarterfinals.
But they were well beaten by Fabian Hurzeler's hungry Brighton, for whom evergreen forward Danny Welbeck scored twice, either side of Milos Kerkez's well-taken goal for the visitors.
Liverpool boss Arne Slot pointed to key injury absentees and a swift turnaround from Champions League commitments to explain the damaging defeat.
The Dutchman was without goalkeeper Alisson Becker and forward Mohamed Salah at the Amex Stadium, while top-scorer Hugo Ekitike limped off early.
Defeat left the reigning champions with only one point from the past nine after they conceded late goals in a 2-1 loss at bottom club Wolves and last weekend's 1-1 draw at home to relegation-threatened Tottenham.
"Brighton away, that's a difficult game for any team, especially if you miss out on a few very influential players," said Slot.
"Of course, now, looking at the league table, this loss hurts a lot and it should hurt us a lot."
Liverpool are still alive in the Champions League and the FA Cup but face the prospect of ending the season trophyless, with daunting quarterfinals to come against Paris Saint-Germain and Manchester City.
Chelsea collapsed to their fourth straight defeat in all competitions against Everton, giving new coach Liam Rosenior a headache as he tries to salvage their season.
The Blues had the chance to go fourth, four points behind United, but they blew it in spectacular style after being outperformed and outworked by David Moyes's men.
Everton's win, courtesy of two goals from Beto and a stunning curler from Iliman Ndiaye, lifted them within three points of neighbors Liverpool with a home Merseyside derby to come next month.
Rosenior, who replaced Enzo Maresca in January, must find a way to lift his expensively assembled squad, who won the Club World Cup and the UEFA Conference League last season.
Chelsea are still in the FA Cup but are licking their wounds after a humiliating 8-2 aggregate defeat by PSG in the last 16 of the Champions League.
"There's been a lot of noise, a lot of negative noise, rightfully so, about our performances in the last week," Rosenior told Sky Sports.
"So we have to forget the noise. We have to keep our confidence and our composure. The international break has probably come at a good time for us to restock, re-energize ourselves and go again for a really important run-in."
Brentford edged ahead of Everton on goal difference after a 0-0 draw at Leeds.
A point took the home side four points above the relegation zone, but that gap could be narrowed by West Ham on Sunday, while Tottenham host Nottingham Forest in a huge clash in the battle to avoid the drop.
