Cosby will take a two-shot lead into tomorrow’s final round of the English Champion Club.
The trio of Coby Blue Cartwright, Luke Burrows and James Billingham (left to right, main image) carded a combined score of three under par to hit the front at Knole Park Golf Club in Kent.
Billingham and Burrows both shot rounds of 68 while Cartwright chipped in with a 71.
That gives the team from Leicestershire and Rutland a narrow advantage over nearest rivals Spalding.
Darryn Lloyd was the star man for the Lincolnshire representatives with a round of 66 and was ably backed up by Simon Richardson (70) and James Crampton (73).
Kedleston Park from Derbyshire currently lie in third spot – helped by a best of the day round from Nick Newbold.
Newbold’s 65 included six birdies and just the one bogey.
A total of 31 teams are competing for the right to follow on from 2019 winners City of Newcastle and go on to represent England at the European Champion Club.
On top of the team prize, there is an individual honour with Newbold one clear of Lloyd and two ahead of Moor Hall’s Rob Bardsley.