The former Cardiff stopper put in a solid display as the Sky Bet Championship club roared into a 2-0 lead against Crystal Palace only to concede a stunning consolation to Owen Garvan's rocket of a volley with just seconds remaining.
And despite his annoyance at conceding, Parish was delighted with his role in the Robins' cup upset.
"I thought I played well and gave the lads a lot of confidence in me," he said.
"I didn't have a lot to do and didn't have a prayer with the goal after the deflection. But really pleased.
"In your head you are really, really angry to concede but you've got to put that to one side and see it out and that is what we did.
"The boys in front of me are really solid and can shut anyone out and they showed that. I wasn't really sure how busy I'd but I was ready for whatever.
"There is massive quality in the squad, we see that every day. It is just about getting to know each other. I think it's really coming on now."
Parish was signed by head coach Sean O'Driscoll after a hugely successful pre-season trial spell and the 23-year-old has sat patiently while fellow summer acquisition Frank Fielding has held the number one shirt.
But having been handed his first start of the season Parish hopes he has left O'Driscoll with a dilemma ahead of the trip to Gillingham.
He said: "Pushing Franky is my ambition whenever I get the opportunity and I hope he (O'Driscoll) is thinking on Saturday 'who do I play?'
"I'm just doing my job and being sharp in training every day and be the best I can be. To push Franky is my aim and to get his shirt."
- Sports & Recreation