Elliott Rushforth scored the only goal of the game as Wokingham and Emmbrook battled past struggling Chinnor at Larges Lane.
The visitors arrived with just four points to their name in Hellenic Division One East this campaign, but they gave a good account of themselves against the Sumas.
Wokingham started well with Josh Harris firing over while Jake White also missed the target.
Chinnor dug in and got in at the break level with Dan Bateman turning to his bench to try and break the deadlock with Ellis Day and Richard Kell introduced.
Pressure was building with Harris again causing problems from midfield and the deadlock was finally broken when Rushforth drilled in after latching onto a loose ball following a free-kick into the area with 20 minutes to play.
Day almost added to the tally and the Sumas were forced to see the game out with 10 men after Chris Robson was shown a straight red card for a late challenge.
Wokingham sit 10th in the table and host Woodley United in the Subsidiary Cup on Tuesday night (7.45pm), needing victory to move into the knock-out round.
SUMAS: O. Holland; Robson, Cummuskey, Marsh, Dean (Kell), Winship (Rowland); Rushforth, Harris, N. Bateman; Clark, White (E. Day). Subs not used: C. Holland, D. Bateman. Attendance: 75.