The winger, who stole the show in England's decisive World Cup double-header against Montenegro and Poland, was rewarded with a new four-year contract on Friday.
And, following an opening half-hour short on chances, Townsend put Tottenham ahead at Villa Park in admittedly fortunate circumstances.
Townsend whipped in a cross from the right which was missed by Lewis Holtby and Roberto Soldado before creeping inside the far post.
He almost scored a second before half-time, but was denied by a smart save from Brad Guzan, who also got down well to keep out Paulinho's volley just after the break.
Paulinho was involved in Spurs' second goal on 69 minutes when the Brazilian midfielder cushioned the ball into the path of Soldado, who took a touch before placing his shot past Guzan for his first Premier League goal in open play since his summer move from Valencia.
The game, however, will also be remembered for a more unsavoury incident after assistant referee David Bryan was struck by a firework thrown from the Spurs supporters' section.
Bryan appeared to be hit on the back of the neck by a flare or smoke bomb thrown amid the celebrations after Townsend's opener.
Spurs boss Andre Villas-Boas made four changes in response to defeat by West Ham last time out as Vlad Chiriches was handed a Premier League debut and Holtby a first start while Sandro and Soldado also came in.
Villa striker Christian Benteke, also returning from injury, was only deemed fit enough for a place on the bench but his second-half introduction almost changed the game before Soldado made sure.
Villa had an early opportunity when Leandro Bacuna's cross found Gabriel Agbonlahor but the striker's shot on the turn flew over.
Spurs enjoyed some good possession without creating any clear-cut chances and Villa were the next to threaten when Ashley Westwood's free-kick bounced awkwardly in front of Hugo Lloris.
Townsend always looked the most likely Spurs player and it was the new England star who broke through just after the half hour, although scoring was clearly not his intention.
Townsend found room on the right and clipped in a cross inviting Holtby and Soldado to attack. Neither were able to get a touch but it mattered little for Spurs as the ball bounced on past Guzan.
Townsend sheepishly accepted the congratulations of his team-mates but attention soon turned to the stands as Bryan was hit by a smoking missile.
The restart was delayed as the matter was cleared up but Bryan appeared unharmed and able to continue. Police and stewards later led away a spectator and the police confirmed after the game that two arrests had been made.
Villa went close to an equaliser as Westwood pulled back a deep cross and Weimann shot narrowly wide.
Townsend almost claimed a second on the stroke of half-time when he brought a good low save out of Guzan from the edge of the area.
Paulinho also tested Guzan in the early stages of the second half, forcing the American to push wide with a shot from distance after a Soldado flick.
Benteke was introduced on the hour and the influential Belgian made an immediate difference to the Villa attack as he went close to equalising when he headed narrowly over from a Bacuna cross six yards out.
Spurs responded to Villa's renewed threat with an incisive attack of their own and claimed the second goal as Soldado latched onto a clever Paulinho pass and calmly clipped past Guzan.
The visitors did not want to finish there and Townsend cut inside to fire a powerful drive inches over the bar.
By now Townsend was rampant as he kept running down the right and his fizzing cross should have brought a third goal, but Paulinho failed to convert the header.