The Spaniard agreed to take charge of the Blues on an interim basis in November but has received frequent abuse from the Stamford Bridge faithful, despite guiding the side to the Europa League final.
Ahead of their meeting on Wednesday, the Portuguese boss, who endured a torrid short spell at Chelsea himself, was full of praise for Benitez.
"Rafa agreed the position of interim manager. It was a difficult situation for him to be in, but you have to say he has been successful because the club's minimum objective is in his grasp going into this game," Villas-Boas told ESPN.
"It is very difficult for me to judge the job he has done, it was difficult for him when he accepted the interim manager position. I have respect for the difficulties that he has gone through."
Chelsea host Spurs in the Premier League on Wednesday night.