Sandown slipped into third in the London South West 3 table, and further away from promotion hopes, with defeat at leaders Old Alleynians.
The side tried their best but were outclassed by Alleynians, who quickly opened up a 19-point lead but were pegged back just before the break when two players were sin-binned, and this allowed Sandown to come back, Frank Bagnall scoring an unconverted try.
Alleynians withstood the pressure in the second half and, when restored to 15 players, extended their lead.
Unconverted tries from Josh Robinson and Luke Chandler were consolation for Sandown, who are three points behind second-placed Old Wellingtonians with two games remaining.
Sandown Team: Harris, Kullick, Eldridge, Hunter, Bagnall, S Rees, J Rees, Gough, Dove, Buckingham, Muir, J Robinson, Chandler, D Robinson, Wales Subs: Marriott, Skelley
Try: Bagnall, J Robinson, Chandler
Conv: -
Pen: -