Colchester United slipped to a 1-0 defeat in their latest Checkatrade Trophy game, as a last minute goal sealed Gillingham's progress to the knock-out stages.
The result means that the U's hopes of escaping the group will go down to their trip at Roots Hall, with Southend currently sitting second after a 1-0 win over Reading U21s on Tuesday night.
In this midweek encounter, the U's had the first sight of goal as weekend goalscorer Murray dragged an early shot wide of the far post.
At the other end, List forced a fingertip save out of Walker with a strike across the U's goalkeeper.
But there followed a good spell of U's pressure as Mandron found himself at the heart of much of Colchester's good work, including setting up Kinsella's shot that brought a good stop out of Arnold in the Gills goal.
Walker then made the save of the half, as he tipped away Clare's bending effort which was bound for the top corner.
The visitors were to finish the first half on the front foot, but the final chance of the half saw Mandron sting the palms of Arnold with a fierce shot from 30 yards out.
Guthrie's evening was to last 45 minutes as he was replaced by Kabamba for the second half.
Early in that second period, Murray's shot was deflected away from the keeper but went just wide of the post with Vincent-Young sliding in.
On the hour mark, Eaves should have given the Gills the lead but lifted his effort over the bar, before Kent blocked well from the impressive Oldaker at the end of a winding run into the box.
At the other end, Odelusi almost got on the end of a ball from the left, before Arnold denied the U's winger and watched as Murray bent his follow up wide.
The match was to be decided with more or less the final kick of the game. Ehmer stepped up to take a late free kick and bent it into the bottom corner to give the Gills the win.