Old Cooperians made it back-to-back wins in the London Three Essex on Saturday by beating Basildon at home.
Andy Yarrow's side picked up a huge 38-0 home victory against the third from bottom side to build on their 43-29 win away at Barking the week before.
They sit eighth in the division, three points behind Kings Cross Steelers in seventh and four points behind sixth-placed Campion.
Campion were not in action over the weekend but are due to take on Chelmsford away on Saturday.
Chelmsford find themselves second having lost just twice this season and beat Campion the last time they met, winning 34-24.
Upminster got back to winning ways after a rare defeat at home to Braintree by beating Kings Cross Steelers away 24-6.
They still sit third in the division and are nine points behind both Chelmsford and Harlow in the places above them.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here