Huddersfield Town ensured Premier League survival after a battling draw at Stamford Bridge damaged Chelsea's hopes of playing in next season's Champions League and left Swansea City on the brink of relegation.
The Terriers produced a defensive masterclass to secure the point they needed to stay up and celebrated wildly with their travelling fans after the final whistle.
The Yorkshire side's supporters chanted "We are staying up" as manager David Wagner was given the bumps by his players on the pitch. Meanwhile, Chelsea manager Antonio Conte waited patiently to shake hands and congratulate every Huddersfield player.
After the visitors linked arms and clapped their fans, Wagner said his team would be celebrating all the way back to Huddersfield.
"We have cancelled the flight and will go home by coach," said the German.
The Terriers did not have a shot on goal in the first half but took a surprise lead in the 50th minute when Laurent Depoitre finished Aaron Mooy's ball over the top.
Chelsea dominated possession but were guilty of some poor finishing.
Antonio Rudiger wasted two glorious chances before the FA Cup finalists finally equalised in fortuitous fashion - Mathias Jorgensen's clearance striking Marcos Alonso in the face before flying into the net.
Huddersfield goalkeeper Jonas Lossl produced a wonderful save to push Andreas Christensen's header onto the post as Chelsea searched for a winner, but the Terriers held firm to ensure a second successive season in the Premier League.
Chelsea must now win away at Newcastle on Sunday and hope Liverpool lose at home to Brighton to qualify for the Champions League.
Meanwhile, at the bottom, Swansea must overturn a nine-goal difference on the final day of the season if they are to stay up.
They have to win at home to relegated Stoke and hope Southampton lose heavily at home to champions Manchester City.