Only a freakish set of results will now deny Burnley a place at the top table of English football against next season after a heroic night in West London took the Clarets to the 40-point mark.
With three games to go, Cardiff City – the club in the final relegation place – will need maximum points to draw level with Sean Dyche’s men, who extended their unbeaten run to four games.
And even with that unlikely scenario, the Welshmen would need to overcome a 17-goal deficit to threaten the Clarets’ position, which also sees them sit above Southampton and Brighton in 15th place.
No-one outside the top four has accrued more than the 28 points Burnley have put on the board in the second half of the season to move towards safety – and that includes Chelsea, who moved back into the top four with a share of the points but may not stay there having played a game more than their rivals for Champions League qualification.
A double-blast from the Blues after Jeff Hendrick’s stunning opener had the home side in front in a crazy opening quarter of an hour.
But Ashley Barnes – the man for the big occasion – swiftly levelled with his 12th goal of a superb season.
And the Clarets then refused to be beaten as they defended with their lives and gave literally everything for the cause to make it all but mission accomplished on another famous away-day in this part of the capital for the joyous travelling supporters.
Stamford Bridge was the scene for the Clarets to light the blue toucher paper for last season’s heroics thanks to their opening-day win.
That day, the Clarets led 3-0 at half time and this time there were four goals shared in a breathless opening 45 minutes.
Stephen Ward’s brilliant volley was arguably the pick of the goals in the Clarets’ first Premier League win over Chelsea and it was matched on this occasion by fellow Irishman Hendrick, who put Burnley ahead to spark a goal-rush of four in 16 frantic minutes.
The Clarets’ first corner of the game was cleared only just beyond the penalty area by Chelsea skipper Cesar Azpilicueta for Hendrick to size up and connect with a wonderful first-time volley which flashed past Kepa Arrizabalaga and into the corner of the net.
The midfielder’s third goal of the season made it 43 in a Premier League campaign for the first time for the Clarets and 1000 conceded by Chelsea in the competition’s history.
But there was more to come on both counts once Chelsea had enjoyed their own fightback.
Eden Hazard had been passed fit to start after shaking off the knock he picked up in helping the Blues reach the semi-finals of the Europa League – a tournament the two clubs have in common this season.
And it was the Chelsea talisman who led the response in dazzling style.
Hazard had already released Gonzalo Higuain for an effort Ben Mee had cleared off the line to set the tone for another peerless performance from the Clarets' lynch-pin when the midfield marvel twisted and turned in the penalty area to tee up N’Golo Kante to lash home the equaliser.
And within two minutes the Blues were in front. Higuain got a lucky bounce to evade Mee’s challenge but the former World Cup finalist then showed his class with an explosive finish into the roof of the net after playing a one-two with the advanced Azpilicueta.
Hazard and Ruben Loftus-Cheek then curled efforts wide but the Clarets refused to buckle and with 24 minutes gone they were level at 2-2.
Again, the goal came from a set-piece as Ashley Westwood swung over a free-kick which Mee headed back across goal.
Wood then flicked the ball on for Barnes to stretch and volley the ball home from inside the six-yard box to complete a remarkable four-timer as he became the only player this season to score against Tottenham, Arsenal, Manchester United and Chelsea.
Aside from a Higuain thunderbolt which flew just, the Clarets nullified the Chelsea response this time.
And the next real chance to add to the score came Burnley’s way seven minutes into the second half as Barnes released Wood for an opportunity he passed up when delaying his shot.
Most of the threat still came from Chelsea, but the Clarets were more measured in keeping them at bay and then were less than 25 minutes to go when Azpilicueta finally tested Tom Heaton with an angled drive at his near post.
And as the clock ticked down the Clarets became even more dogged in their defiance, fully aware of the prize at stake for themselves and Chelsea as they frustrated the Blues’ Champions League qualification prospects.
It was a heroic effort as the home side were kept at arm’s length, with Burnley's back four outstanding to a man - Matt Lowton responding superbly to a testing start to put the brakes on Hazard - and those in front running themselves into the ground.
With temperatures reaching boiling point on a sultry night, passions ran high and off the pitch at the end.
But nothing could deter Burnley from celebrating the point that has surely guaranteed a fourth successive season of Premier League football.
Burnley: Heaton, Lowton, Tarkowski, Mee, Taylor, Hendrick, Westwood, Cork, McNeil, Barnes, Wood. Substitutes: Hart, Gudmundsson, Brady, Gibson, Ward, Vydra, Long.
Chelsea: Arrizabalaga; Azpilicueta, Christensen, Luiz, Emerson; Kante (Kovacic HT), Jorginho, Loftus-Cheek; Hudson-Odoi (Pedro 41), Higuain (Giroud 77), Hazard. Substitutes: Caballero, Barkley, Zappacosta, Cahill.
Booked: Kovacic, Pedro
Referee: Kevin Friend