The England international followed up his recent heroics in the climactic World Cup qualifiers with the opening goal and a devastating display of attacking football as Spurs went fifth in the Barclays Premier League.
Townsend broke the deadlock after 31 minutes - albeit with a cross-cum-shot - before forcing Brad Guzan into a fine save and shooting inches over the bar.
Summer signing Roberto Soldado wrapped up the victory with the second goal after 69 minutes.
Villas-Boas said of Townsend: "I think it was a great performance. Alongside the team, it grew in the second half and he really improved his performance.
"He gives us so many attacking options because he is able to take the team forward with his driving ability and link-up play, crossing, assisting.
"It was another great performance, like we saw for his country. It was great to see."
Townsend, 22, spent the end of last season on loan at QPR, the most recent of nine temporary moves in his career.
The former trainee has only risen to prominence at White Hart Lane this season but he has grasped his chance and his displays for England this month have seen his profile soar.
Villas-Boas said: "I think the loan really worked for him. He came with the right frame of mind to grab the opportunity.
"I think he has shown all his drive and motivation to stay at Spurs this season and we are glad to have him."
Townsend is now keeping England international Aaron Lennon and B£30million signing Erik Lamela out of the side.
Villas-Boas said: "We have five wingers for two places, so the competition is very high.
"The players know they can't drop their performance. It is with performances like this (where) you can keep your place."