Their 3-1 win over the pre-season promotion favourites followed an eye-catching three points away at Fleetwood.
Those results have moved the Pirates to within goal difference of safety at the foot of npower League Two, with 22nd-placed Plymouth having played two games more.
And Parkes says his side can be confident going into games against Barnet and Cheltenham in the next seven days.
"We are on a bit of a high at the moment," he told this is Bristol.
"We've taken 10 points from a possible 15 over the last five games and are off the bottom of the league.
"We are still in the bottom two, but our last couple of results suggest that we certainly are a different and much tougher proposition at the moment.
"I think a lot of other teams would have looked at us a couple of months ago and fancied themselves to beat us every time, but we are a lot stronger now."
- Sports & Recreation