The Western Force ended the Chiefs unbeaten run in Super Rugby in 2014 with an 18-15 victory in Perth on Saturday.
The victory is the first time that the Force have gone three matches unbeaten since 2007 and and their second victory in eight clashes with the powerful Chiefs.
The Force scored the only tries of the match - both through captain Matt Hodgson and almost scored a third but Nick Cummins slipped a foot into touch.
The result is also first time that the Chiefs have been held tryless in Australia since 2001.
The loss for the Chiefs means that the Sharks in Durban South Africa are the only unbeaten team.
The Force, beaten badly by the Waratahs and Brumbies in their first two games of the season, moved to fifth on the table with the upset.
Sustained pressure from the Force led to an uncharacteristic 15 handling errors from the Chiefs, to the home team's five.
It was a well-deserved win for the Force, who not only scored the only two tries, but also twice crossed unsuccessfully.
Force skipper Matt Hodgson was the hero, scoring both tries, his first brace in 102 games of Super Rugby.
He was also held up over the line on another occasion, while Nick Cummins dived over in the corner, but his left foot stepped into touch as he lunged at the line.
In contrast, the Chiefs never got their game going and the couple of times they threatened the Force defence held firm.
It was almost fitting that the Chiefs' last two forward surges ended with ball-handling errors, a pair of knock-ons.
The visitors had a final chance when they regained possession just as the final hooter sounded, but again lost the ball forward.
Hodgson said the Force always believed they could turn around their slow start to the season and had set themselves to deny the Chiefs their running game.
"There is great belief in this group, we knew we could do it," he said.
"Now we are putting it on the board, which is great."
Chiefs captain Aaron Cruden said his team lacked the necessary desire.
"They grow an arm and a leg here at this stadium," he said.
"They deserved the win, they wanted it more than us."
Final Score Western Force 18 (8) Chiefs 15 (9)
Tries - M.Hodgson 2
Pen - S.Ebersohn 2
Con - S.Ebersohn
Pen - A.Cruden 4,G. Anscombe
Cards - J. Mackintosh (35th min yellow)
Referee: Lourens van der Merwe
Assistant Ref 1:Angus Gardner
Assistant Ref 2:Will Houston
TMO : Steve Leszczynski
1. Pek Cowan,2. Nathan Charles,3. Kieran Longbottom,4. Sam Wykes ,5. Wilhelm Steenkamp ,6. Hugh McMeniman,7. Matt Hodgson (c),8. Angus Cottrell,9. Alby Mathewson,10. Sias Ebersohn,11. Nick Cummins ,12. Kyle Godwin,13. Junior Rasolea,14. Luke Morahan ,15. Jayden Hayward
Replacements : 16. Heath Tessmann,17. Tetera Faulkner ,18. Ollie Hoskins,19. Adam Coleman,20. Brynard Stander,21. Ian Prior,22. Zack Holmes ,23. Marcel Brache
1. Jamie Mackintosh,2. Mahonri Schwalger,3. Ben Tameifuna ,4. Michael Fitzgerald ,5. Brodie Retallick,6. Liam Messam,7. Sam Cane ,8. Liam Squire,9. Tawera Kerr-Barlow,10. Aaron Cruden (c),11. Asaeli Tikoirotuma ,12. Tom Marshall, 13. Tim Nanai-Williams ,14. Mils Muliaina ,15. Gareth Anscombe
Replacements :16. Rhys Marshall,17. Pauliasi Manu ,18. Josh Hohneck,19. Kane Thompson ,20. Tanerau Latimer,21. Augustine Pulu ,22. Andrew Horrell ,23. Anton Lienert-Brown