Heading into the first of two final qualifying games for the World Cup, the Three Lions knew only maximum points would guarantee a place at next summer's tournament - and controlled the game with over 60 percent possession.
Rooney opened the scoring early in the second half after a frustrating opening 45 minutes, before an own goal by Branko Boskovic, a stunning 25-yard debut goal by Andros Townsend and a Daniel Sturridge penalty sealed three points.
"It was great," Rooney told Sky Sports. "Exciting, with a lot of speed and with experience of Steve [Gerrard] and Frank [Lampard] behind us.
"The manager gave us the freedom and platform to go out and express ourselves and I thought the four of us did that, especially Andros [Townsend], that was some debut."
Rooney commended Montenegro for its performance, but believes his opening goal was key to breaking down the side England has failed to beat on all three previous occasions.
"It was a tough game," he continued. "First half they defended deep and defended well but we still created a few opportunities. So we came in at halftime knowing we could create chances against Montenegro.
"I think getting the goal so early in the second half was vital and we excelled after that and deserved the three points. I think you saw a weight come off everyone's shoulders. It was always going to be a night where we had to be patient and try and break them down but getting that goal was vital for us."
England hosts Poland on Tuesday with a second-place finish all but guaranteed, while Ukraine will look to take advantage of any slip up when it travels to San Marino.