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."
Roy Hodgson trusts his young England side to finish the World Cup qualifying job in style with a victory against Poland at Wembley on Tuesday.
The England manager saw his bold move to select 22-year-old Tottenham winger Andros Townsend for his debut pay off spectacularly when he scored a stunning goal and picked up the man-of-the-match award in Friday's 4-1 win against Montenegro.
He now believes England, who top Group H after an unbeaten campaign so far, will book their flights to Brazil next summer, although he has warned his men against complacency.
Hodgson said: "The job's half done. If we want to qualify direct we need to win against Poland on Tuesday night. That won't be easy. That will be very difficult.
"If they play as well against us on Tuesday as they did against Ukraine it will be a tough game."
Ukraine beat Poland to stay one point behind England and have a footballing 'gimme' with their last fixture against San Marino.
Hodgson, however, said: "I always back the players. I trust them. We are still unbeaten in this qualifying group. We are capable of going unbeaten in the 10th one and with the backing we got from the fans and playing at Wembley I have got to back them. I would be foolish not to."
Wayne Rooney scored the opening goal against Montenegro at Wembley, which was swiftly followed by a bizarre own goal from Branko Boskovic.
Dejan Damjanovic pulled one back for Montenegro but 22-year-old Townsend's strike and a late penalty from Daniel Sturridge after he was brought down in the area clinched the victory.
Hodgson admitted the selection of Townsend was a tough decision but said: "He made a big impact. He got the man of the match which he must be delighted with. It can't be easy for a young man making his debut in a game of that nature.
"He deserves all the credit which I am sure he is going to get because he played well, with a calmness and composure which I have seen him play with for QPR and most recently Tottenham. I was fortunate he was able to reproduce it.
"We had a lot of time to think about our selection. It was not easy to leave people like James Milner and Jack Wilshere out, as they also bring a lot of attacking flair.
"We thought Townsend's pace against a packed defence would open doors. He really performed on the night."
NU-MAD - WE TELL IT AS IT IS!
Join us on Facebook
PLEASE join Newcastle Utd-Mad on Facebook:-
NEWCASTLE UNITED 2013/14
CARDIFF CITY 1 NEWCASTLE 2 (Remy 2)
Krul, Debuchy, Williamson, Coloccini, Santon, Tiote, Cabaye (86' Ben Arfa), Gouffran, Sissoko, Remy (71' Gutierrez), Cisse
Subs: Anita, Yanga-Mbiwa, Elliot, Sammy Ameobi, Dummett
EVERTON 3 NEWCASTLE 2 (Cabaye, Remy)
Krul, Debuchy, Yanga-Mbiwa (46' Williamson), Coloccini, Santon, Tiote, Anita (69' Cisse), Ben Arfa (46' Cabaye), Sissoko, Gouffran, Remy
Subs: Elliot, Obertan, Sammy Ameobi, Dummett
NEWCASTLE 2 HULL CITY 3 (Remy 2)
Krul, Debuchy (86' Tiote), Yanga-Mbiwa, Coloccini, Santon, Cabaye (62' Gouffran), Anita, Sissoko, Ben Arfa, Cisse (73' Marveaux), Remy
Subs: Williamson, Elliot, Sammy Ameobi, Dummett
ASTON VILLA 1 NEWCASTLE 2 (Ben Arfra, Gouffran)
Krul, Debuchy, Coloccini, Yanga-Mbiwa, Santon, Anita (74' Tiote), Cabaye (88' Sammy Ameobi), Ben Arfa, Sissoko, Remy (63' Gouffran), Cisse
Subs: Elliot, Marveaux, S Taylor, Dummett
NEWCASTLE 1 FULHAM 0 (Ben Arfa)
Krul, Debuchy, Yanga-Mbiwa, Coloccini, Santon, Ben Arfa, Sissoko, Anita 65' (Cabaye), Marveaux 74' (Remy), Shola Ameobi 65' (Gouffran), Cisse
Subs: Gosling, Elliot, Sammy Ameobi, Dummett
NEWCASTLE 0 WEST HAM 0
Krul, Debuchy, Yanga-Mbiwa, Coloccini, Santon, Ben Arfa, Sissoko, Anita, Marveaux 66' (Sammy Ameobi), Shola Ameobi, Cisse 72'
Subs: Gosling, Bigirimana, Elliot, Vuckic, Dummett
MAN CITY 4 NEWCASTLE 0
Krul, Debuchy, Coloccini, S Taylor, Yanga-Mbiwa, Sissoko, Tiote, Gouffran 45+4' (Dummett), Ben Arfa 65' (Sammy Ameobi), Gutierrez 44' (Anita), Cisse
Subs: Elliot, Marveaux, Shola Ameobi, Obertan
NEWCASTLE 2 LEEDS UTD 0 (Cisse, Gouffran)
Krul, Debuchy, Williamson, Coloccini, Dummett, Gouffran (90' Vuckic), Anita (80' Gosling), Tiote, Marveaux, Sammy Ameobi, Cisse (71' Obertan).
Subs: Ben Arfa, Yanga-Mbiwa, Bigirimana, Alnwick
MORECAMBE 0 NEWCASTLE 2 (Shola Ameobi, Sammy Ameobi)
Elliot, Debuchy, Yanga-Mbiwa, Good, Dummett, Bigirimana, Gosling, Marveaux 88' (Sissoko), Vuckic 46' (Shola Ameobi), Sammy Ameobi, Gouffran 71' (Ben Arfa)
Subs: Santon, Anita, Alnwick, Streete
Newcastle United Fixtures
Saturday October 19
12:45 Premier League
Newcastle United v Liverpool
Sunday October 27
13:30 Premier League
Sunderland v Newcastle United
Wednesday October 30
19:45 League Cup - 4th Rnd
Newcastle United v Manchester City
Saturday November 2
12:45 Premier League
Newcastle United v Chelsea
Sunday November 10
12:00 Premier League
Tottenham v Newcastle United