Townsend scored a stunning second-half goal and picked up the man-of-the-match award on his debut as England beat Montenegro 4-1 at Wembley in their qualifier to stay in control of Group H.
If Hodgson's side beat Poland at Wembley on Tuesday they will qualify for Brazil next summer.
Wayne Rooney scored the opening goal after a nervy first half and that was followed up 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 one but said: "The most important goal really was Andros's third because that restored our two-goal margin.
"Andros's goal took the wind out of their sails and gave us time to compose ourselves again.
"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 tonight.
"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."
Hodgson, however, admitted there were nerves, especially when he realised Ukraine had beaten Poland to temporarily leapfrog England at the top of the group.
"There is always anxiety," said Hodgson. "We knew it was 1-0. I knew Ukraine had scored so there was some anxiety. For all our possession, corner kicks and attempts we had two very good goal chances but one always fears we will come against a wall of players and not find our way through.
"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. I watched them, in the first half they played very well against Ukraine. They had the best goal-scoring opportunities.
"If they play as well against us on Tuesday as they did against Ukraine in the first it will be a tough game.
"But 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."
Hodgson plans to draft a player from the Under-21s into his squad to replace Manchester United's Tom Cleverley who has a calf problem.
Montenegro manager Branko Brnovic tipped England to beat Poland on Tuesday and finish top of the group.
He said: "England have definitely a great team. I don't know whether Poland will be motivated in their last match and I am sure England will head the group.
"I'm sad about the result, but it was a huge experience for our young team. England were the better team."
Brnovic was particularly impressed by Townsend.
He said: "He's very fast, a high quality player. The whole team is very fast. We had some problems with that and that is why they won.
"After 2-0 we lost our pace. I can't say what it would have been if we had all our best players. We missed a couple.
"Before this we were planning to be second in the group, but we are third and not satisfied with this."