Burnley produced the first shock result of the Premier League season, beating champions Chelsea with a remarkable performance at Stamford Bridge.
The sending off of Blues captain Gary Cahill set the hosts spiralling out of control, as a Sam Vokes brace either side of a superbly struck Stephen Ward effort put Burnley 3-0 up at the break.
Chelsea very nearly completed a dramatic comeback in the second half, with goals from substitute Alvaro Morata and David Luiz, but a red card for Cesc Fabregas meant that their attempt to recover was carried out with nine men, and Burnley were resolute enough to secure the win.
A relatively uneventful opening to the game was brought swiftly to life when Cahill, stretching for a lose ball, lunged in on Steven Defour and was given a straight red card.
It was a start that seemed to typify the mood around Chelsea prior to kick-off, and in turn invigorated the visitors.
And with 23 minutes played, a well guided volley from Vokes put Burnley in front with what was the first real opportunity of the game.
Chelsea offered little in immediate response against a compact and organised Burnley side, who were growing increasingly comfortable with the advantage of an extra man.
That confidence was demonstrated even further when Ward, chesting the ball just inside the box, hit a superb, emphatically struck half volley from a tight angle past Thibaut Courtois to double his side's lead.
It wasn't to be the end of the first half scoring. Stamford Bridge was left stunned minutes later when Vokes was picked out in the box and powered a header to score his second and, almost unbelievably, Burnley's third.
14': Gary Cahill gets sent off— Squawka News (@SquawkaNews) August 12, 2017
24': Chelsea 0-1 Burnley
39': Chelsea 0-2 Burnley
43': Chelsea 0-3 Burnley
Chelsea capitulating. pic.twitter.com/mRqhoXQYNz
Having left the pitch to boos, Chelsea required a quick improvement on their return for the second half. They offered an element of pressure on the Burnley goal, but clear chances continued to prove elusive and there was a distinct lack of creativity from those in a blue shirt.
An increasingly frustrated and vitriolic home support attempted to instigate the beginnings of a Chelsea turnaround, raising the noise levels as Chelsea searched for a goal back.
And with just over 20 minutes remaining, Premier League debutant Morata - who had replaced the inauspicious Michy Batshuayi - met an excellent Willian cross and guided a header into the far corner.
The Spanish forward thought he had another minutes later, but his close range finish was ruled out for offside.
Chelsea appeared to be gathering some momentum, until Fabregas lunged into a challenge and picked up a second yellow card, leaving the hosts with nine men for the final ten minutes.
With two extra men, and a two goal lead intact, Burnley looked set to hold on. But Chelsea weren't finished. Luiz pulled another goal back for the home side, two minutes from time, with a left-footed finish past Tom Heaton, and a tense end to the game ensued.
Robbie Brady struck the Chelsea post with a late free-kick as Burnley looked to hold on, and despite the home side's desperate attempts to find an equaliser, it proved to be the final chance.