Captain Marcus North says Glamorgan want to make amends for their disappointing T20 campaign by being successful in the Yorkshire Bank 40.
Glamorgan claimed a 11 run win over Middlesex to keep their hopes of a semi-final place in the YB40 alive.
The Welsh county failed to reach the knockout stages in the T20 despite targeting the competition.
"This is the competition where we want to make amends for how we finished in the T20," said North.
"We have some good momentum from the first two games and it's good we have the next three games pretty close together.
"When you find a rhythm, you want to continue to play. We cannot wait for Gloucestershire."
Glamorgan face Gloucestershire, who are level on them with 13 points in Pool C, in Bristol on Sunday.
"A win against Somerset and a win against Middlesex, it sets us up for a big game on Sunday against Gloucester," said North.
Glamorgan have three pool matches left and are level with Gloucestershire who have also played nine games, and Somerset who have played one game more.
"We have a lot of confidence now and that was a huge win," said North.
"Against Somerset, the outcome was probably the most important thing. The way we won was a little bit disappointing with our batting at the end with the collapse.
"I thought we saw a genuine team effort (against Middlesex) in tough conditions and it is a huge advantage bowling here, so to win bowling second is outstanding."