Beaconsfield 3rd edged to a 14-run over Cookham Dean 3rd to stay third in Division 8B.
Thanks to Simon Ward (39) and Mark Polloway (38), Beaconsfield made 182-8 in their 40 overs.
Cook were then restricted to 168-7 in reply, the key spell coming from Liam Nash, whom took 2-23 in ten overs.