The Chiefs have staged a stunning six-try comeback to upset the defending champions, and runaway Super Rugby leaders the Crusaders, 40 points to 27 on a hot humid night in Suva.
Waikato came from 20-0 down after 21 minutes to hand the competition leaders just their second defeat of the season after a breathless 80 minutes in the heat of Fiji's National Stadium.
Bottom of the New Zealand conference and 26 points behind the double defending champions at the start of the contest, the Chiefs looked destined for defeat when they conceded three unanswered tries in 11 minutes.
Tries from fullback Solomon Alaimalo, hooker Samisoni Taukei'aho and lock Jesse Parete sent them into the break only a point down, however, and better was to come in the second half.
Winger Braydon Ennor stretched the Crusaders' lead just after the resumption but the Chiefs, running the ball from everywhere, hit back through scrumhalf Brad Weber and hit the front courtesy of a blistering run from outside back Shaun Stevenson.
Holding a six-point lead with 13 minutes remaining, the Chiefs still eschewed the conservative, and replacement back Tumua Manu snatched a 22 dropout out of the air to seal a famous victory with a sixth try two minutes from time.