Totesport League Division One, Cheltenham: Gloucestershire 182 (44.1 overs) beat Essex 122 (38.4 overs) by 60 runs
Gloucestershire turned the Totesport Division One table on its head at Cheltenham to inflict leaders Essex's first defeat of the season.
They won a low-scoring game by 60 runs by bowling out Essex for 122.
Gloucestershire lost both openers to Darren Gough for ducks and were all out for 182 despite 57 from Matt Windows and a rapid 36 by Malinga Bandara.
But Averis produced a superb spell of 2-9 in reply and there was no way back for Essex after crumbling to 49-7.
They were finally dismissed in the 39th over when top scorer Andre Adams was caught by Bandara off Hardinges after hitting three sixes in his 46.
Ravi Bopara (20) was not the next highest score for Essex, who lost Grant Flower to the first ball of their innings when he edged a ball from Averis to the keeper.
Flower had earlier been the pick of Essex's attack, returning figures of 3-26 with his left-arm spin, while Gough picked up 3-36.