The Indian spinners, led by Ravichandran Ashwin (3/39), shot England out for a modest 227 before Rayudu top-scored with an unbeaten 64 to fashion an easy victory over the home side.
"The spinners did it for us. Ashwin and (Ravindra) Jadeja did really well, but it was also Raina's spell after Mohit's injury," Dhoni said after the match which India won with 42 balls to spare.
Rayudu and Raina took one wicket each before contributing 64 not out and 42 in India's successful run chase.
Dhoni said he never thought the Trent Bridge wicket would turn appreciably but it did to the delight of Indian spinners.
"I never thought it would spin and in the back of my mind I was wary the ball would not do a lot. When I saw the pitch today it had some green but I think after the first 20 minutes or so it dried up and slowed down," he said.
"Raina also bowled well and he gave us the first breakthrough. Rayudu also got a wicket. Both of them took us through in the run chase later on," Dhoni added.
The Indian skipper said that Rayudu could be in contention for the number four slot in the ODI team.
"Rayudu did very well, we are still looking for a number four batsman and there are a few out there."
Asked about Virat Kohli who put himself in with a 40 but failed to convert it to a big score, Dhoni said a big knock could be in the offing from the Delhi batsman very soon.
"Virat is in a bad patch but he is an aggressive player who has the fighter's attitude. He has been middling the balls and it is only that he could not convert the starts into big ones.
"I can say that a big knock is around the corner from Virat."