Manchester United striker Rooney netted his sixth goal in five qualifiers before a bizarre Branko Boskovic own goal, debutant Townsend's stunning strike and a late Daniel Sturridge penalty.
It means England's World Cup fate remains in their hands ahead of Tuesday's match with Poland.
Rooney, whose strike was his 37th England goal, reserved special praise for Townsend.
"It was some debut," he said.
"In such a high-pressure game to perform like that was incredible."
Rooney enjoyed being part of an exciting attacking quartet.
He added: "It was great. A lot of speed and the experience of Steve (Gerrard) and Frank (Lampard) behind us.
"The manager gave us the freedom and the platform to go out and express ourselves."
The United striker knew England might have to wait to take their opportunity in a must-win match which means victory over Poland will secure a place at the finals in Brazil next summer.
"It was a tough game," Rooney said.
"I thought it was always a night when we were going to have to be patient and try to break them down.
"First half they defended deep, defended well. Getting the goal so early on in the second half was vital and I thought we fully deserved the three points.
"You saw a weight come off everyone's shoulders and we played some good stuff, created chances."