Villas-Boas' Spurs have picked up considerably after a slow start, with three wins and a draw in their last four games.
Defoe played a big part with five goals and Villas-Boas said he is delighted with the striker's form.
"For a striker, goals are absolutely decisive and he has four in the Premier League," he said. "He's not far from being the Premier League's top scorer. But he's been creating so much and been immense for the team.
"We have to be very grateful for what he has been doing for the team. I think he is enjoying every moment of it. He has performed so well for this club and you have to respect the fact he keeps on motivating himself to show that.
"Now he is getting confidence from being given games from the start. He has been excellent. His performance, his desire, his motivation are there and his movements are fantastic."