Bottom of the table Plymouth Devils shocked second-placed Sheffield to win 46-44 in the Premier League.
Ricky Wells and Jesper Kristiansen were the heroes for the Devils as they recorded a final- heat maximum to turn a likely loss into a win.
Wells top-scored for Plymouth with 13+1 while Kristiansen finished with 12.
Plymouth remain bottom of the Premier League six points adrift of Leicester but with six matches in hand on the Midlanders.
The win proved more remarkable after Devils lost their talisman and captain Ben Barker after just one race.
The Team Great Britain rider will now require an operation to remove a metal plate in his leg and could face a spell on the sidelines.