Spurs were far from their best against Southampton and could easily have been trailing at half-time after Nathaniel Clyne missed a great chance and Rickie Lambert struck the post.
But the home side improved after the break and claimed all three points on 86 minutes when Bale cut in from the right before unleashing a powerful shot beyond Artur Boruc to sink his former club.
Bale's winner capped a memorable week for the Wales international, who has been named PFA Player of the Year, Young Player of the Year and the Football Writers' Association's Footballer of the Year.
"Again, it was decided by a great moment of individual brilliance," Villas-Boas told Sky Sports.
"We kept on pushing and Gareth played in three different positions today - as striker, then on the left and on the right to try and get the best out of him.
"He is enjoying his football, but Southampton dealt with him very, very well and were very organised.
"But in the last gasp, they conceded a little bit more space, probably because we wore them out a little bit in the second half and we managed to get the winner."
Bale's goal was his 20th in the Premier League this season and Villas-Boas said: "I think it's an achievement for any footballer, but especially for a player who hasn't started as a striker in the beginning of the season.
"He missed some games through injury and he's now on a great, great run of form and he is really enjoying his moment."
The win sets up Spurs for a crucial game against Chelsea in midweek which could go a long way to determining which club finishes in the top four.
Ahead of the visit to his former club, Villas-Boas added: "We are going to give it a try. If we win our games, we are there, so we have to push to get this result and hopefully we can achieve that."