The Brazilian has started every league game this season and has rewarded his Portuguese boss with two goals.
The 24-year-old often struggled under Carlo Ancelotti and he notes Villas-Boas as a major factor in his improved form.
"I knew him from Portugal, I remember playing against Academica when he became their manager two seasons ago when I was with Benfica," Ramires told the club's official website.
"Having the opportunity to meet him here is fantastic because I admire the work he did in Porto immensely and the person he is as well means he is the best trainer I have ever had.
"He is always giving you strength and belief, supporting you and telling you what you need to do.
"He is absolutely fantastic, very intelligent and understands the game amazingly well," he explained.
Ramires has been overlooked for his national side since the Copa America but he insists he is settled at Stamford Bridge and is looking to win the Premier League with the club.
"I've said before that I am very happy with how things are for me at the club at the moment, and it isn't just for me but the whole team which has been growing with every match and competition.
"I hope we can continue this good phase for a very long time and win some titles, which I have not done for Chelsea yet," he said.