Banbury twice appeared to have built up a winning position against leaders Slough on Saturday but ended up losing the game by 28 runs.
After being put in to bat, Slough made a bright start, but the introduction of talented young left-arm spiner Luke Ryan into the attack slowed them down.
The 17-year-old dismissed both openers, and with Paul Taylor chipping in with useful wickets, Slough seemed to be struggling at 174-8.
But Steve Naylor was still there and he dominated an unbroken ninth-wicket partnership of 51 to take Slough to 225-8 from their 66 overs.
Naylor finished on 81 not out, while Ryan returned 4-85 from 25 excellent overs.
The game was in the balance at the start of Banbury’s reply, but openers Chris Smith and Benji Hector put their side in a commanding posotion.
Fresh from his big hundred for Oxfordshire in midweek, Smith hit 31, while skipper Hector made 57 as the pair put on 82 for the first wicket.
But apart from Richard Kaufman (34), no other batsman made a significant contribution as wickets fell steadily to the varied Slough attack.
Eventually, they were dismissed for 197 when Simon Launder was bowled by Waqar Ahmed by the fourth ball of the penultimate over.
With Wycombe losing surprisingly to West Herts, Slough extended their lead at the top to a commanding 39 points.