AmaZulu now turn their focus to improving their league position and meet City again on Saturday night - but this time away from home.
"The players are excited about that now, this win has been so important for us," added Johnson.
"It will be a lot different because we'll play a City team with players coming back from suspension [Taariq Fielies and Roland Putsche] and I'm sure they will have a different approach. It means we are going to have to come up with a different plan."
Johnson was also pleased with the Telkom Knockout quarterfinal draw where they will host Orlando Pirates.
"We'll have a packed King Zwelithini Stadium. Pirates have been here already this season and we showed [them that] we could play against them."