Chelsea's hopes of chasing down Manchester United at the top of the table suffered a huge blow on Saturday as they crashed to defeat at Liverpool, whilst Charlton enjoyed a productive afternoon at the bottom as Watford lost and West Ham drew.
Aston Villa and Middlesbrough also secured morale-boosting wins, whilst Reading beat Sheffield United and Tottenham were held at Craven Cottage.
Liverpool ended their run of five league defeats in a row against Chelsea to deal a telling blow to The Blues' title hopes with a 2-0 win at Anfield.
Jose Mourinho's lack of options in defence was cruelly exposed within the first five minutes as Dirk Kuyt latched onto Peter Crouch's header and finished calmly past the returning Petr Cech.
On 18 minutes, Jermaine Pennant deepened the gloom at Stamford Bridge with a superb second to seal a result that is unlikely to help repair Mourinho's seemingly fractious relationship with Roman Abramovich.
The Reds are now just five points shy of the reigning Champions, but only after Sunday's game between Manchester United and Arsenal will the real repercussions of the win be made clear.
Charlton picked up a precious victory to move to within three points of safety following a 1-0 win at Portsmouth.
Amdy Faye scored his first goal for The Addicks against his former club with 11 minutes to go as he looped a shot over David James to give Alan Pardew a fighting chance of avoiding the drop.
West Ham let a two-goal lead slip as they drew 2-2 with Newcastle United at St James' Park, leaving them just one point ahead of Charlton.
The Hammers took control when strike partners Carlton Cole (1
and Marlon Harewood (22) both showed their predatory instincts, but Newcastle levelled in controversial circumstances when James Milner's shot went through Scott Parker's legs as the Magpies captain was standing in an offside position.
After half-time, Nobby Solano converted from the penalty spot after a hand-ball from Luis Boa Morte (53) to give Newcastle a point.
Bottom club Watford now have a ten-point chasm to close after allowing Aston Villa to end a 12-game winless streak with a 2-0 victory at Villa Park.
Martin O'Neill's side took the lead in lucky circumstances when Gavin McCann's shot took a deflection off both Malky Mackay and Gavin Mahon with just four minutes to go, and Gabriel Agbonlahor had time to make sure of the win in injury-time.
Middlesbrough enjoyed a thumping 5-1 win over Bolton Wanderers - who missed the chance to climb above Arsenal into fourth.
Boro raced into a 4-1 lead before half-time, with Abel Xavier the unlikely threat early on as his header deflected back off the post and in off the unfortunate Gary Speed (6).
The Portuguese defender then headed home himself (10), and after Mark Viduka's neat first-time finish at the back post (23), Kevin Nolan pulled one back for Bolton with a composed strike from the edge of the box.
The excellent Stewart Downing rifled home a rare right-footed effort with two minutes to go before the break, and Viduka added his second (84) after the dismissal of El Hadji Diouf (66) for foul and abusive language.
Reading won the battle of the two promoted sides at The Madejski Stadium as they beat Sheffield United 3-1 in a bad tempered encounter.
Shane Long, deputising for the injured Kevin Doyle, picked up where his compatriot had left off with a close-range finish (44), and Ulises de la Cruz added a second on 50 minutes before the game erupted when substitute Keith Gillespie was dismissed for use of the elbow on Stephen Hunt.
The incident sparked an unseemly brawl between the two benches, with Reading assistant Wally Downes and Neil Warnock sent to the stands, and Hunt had the last laugh when he scored a third with 20 minutes to go.
However Christian Nade grabbed a consolation (77) when Reading's offside trap from a free-kick went horribly wrong.
European hopefuls Tottenham were held to a 1-1 draw at Fulham in a game that witnessed a dramatic conclusion following Heidar Helguson's dismissal (53).
The Cottagers took the lead from the penalty after a dubious handball decision against Michael Dawson, with Vincenzo Montella (84) stroking home for his first Premiership goal.
However Pascal Chimbonda popped up four minutes later for an equaliser.
In the evening kick-off, Blackburn Rovers moved into tenth as goals from Morten Gamst Pedersen (44, 62) and Matt Derbyshire (90) gave them a 3-0 win at Manchester City.