The Welshman scored two free kicks at White Hart Lane, including one in injury time, to give Spurs the advantage after the first leg of their last-32 tie.
"It is incredible. Not only his all-round game but also this ability he has to strike these free kicks," Villas-Boas told Sky Sports News.
"The ball gains so much power when he strikes it and it changes direction so easily."
Spurs travel to France for the return leg next Thursday.