Jacob Butterfield’s sublime goal on eight minutes proved to be enough as the Rams displayed both sides of the game, firstly by playing quick football, before showing resilience to keep Rovers at bay in the second half.
The victory at the iPro Stadium saw Wassall’s side secure back-to-back wins in the Sky Bet Championship as Derby kept chase with the division’s leading pack.
Speaking after the game, Johnson has praised the Head Coach’s motivation techniques.
The 28-year-old told Rams Player HD: “The confidence is coming back and Wass (Darren Wassall) deserves a lot of credit for the way he has motivated us.
“We are playing with freedom now, we are confident, and long may that continue.
“It was important to carry on our form from Saturday. Back-to-back wins in this league is a good achievement and we knew that we needed to put in a performance to mirror how well we played on Saturday.
“It was a hard game for us, Blackburn threw everything at us, but I thought we defended really well.
“That starts with Chrissy (Chris Martin) and stems right back to Scotty (Scott Carson), who pulled off a great save in the second half.
“Rich (Richard Keogh) and Shacks (Jason Shackell) at the back were outstanding. A win is a win and we got the three points, which is all that matters.”
He added: “Teams are going to come here and try and make it hard for us and Blackburn did that.
“We thought they would tire, especially with them playing on Sunday, but they didn’t and they put us under a lot of pressure in the second half.
“They threw bodies up front and in the last few minutes, they had four men playing up there – all big lads and they really did throw everything at us.
“We dealt with their threats, though, and we have given ourselves another platform to build on for Saturday now.”
The Rams make the short trip to Molineux to take on Wolverhampton Wanderers in the early Championship kick-off on Saturday 27 February, (12:30pm).
With an opportunity to, albeit temporarily, cut the gap on the teams above them at the top of the league Johnson has called on his team mates to replicate the same ‘attitude and work rate’ that they have produced in their past two fixtures.
“That’s something we are focusing on,” Johnson said. “Like we had to for Brentford, we have got to back this up when we face Wolves.
“We put in a great performance and all the players came off the pitch at the end knackered, but we have got a couple of days now to prepare for Saturday.
“This is the business end of the season now. We have got 13 games left and it is down to us.
“We can’t concentrate on other teams, we can only focus on our performances and make sure that we go on a good run.
“We have done that before and we know we are capable of doing it again.
“The past two games have given us great confidence and we now need to approach Saturday with the same attitude and work rate and I’m sure we will have a good chance of getting the result that we want.”