The prolific opener scored 63 on Sunday, following up his 159 in the second match and ended as the top scorer of the series with 258 runs.
Continuing their good run at the top of the order, Rohit and K.L. Rahul added 122 runs on Sunday.
"We wanted to make runs upfront. But great to see the way Virat (Kohli) and KL (Rahul) batted and (Ravindra) Jadeja at the end. I quite enjoyed Shardul's (Thakur) pull shot, even if it was a top edge," he said.
The win caps an extraordinary year for Rohit in which he scored 2,442 runs across formats. Only captain Virat Kohli has scored more than him in world cricket this year.
On Sunday, Rohit also surpassed Sri Lankan great Sanath Jayasuriya's 22-year-old record for most runs as an opener in a calendar year across formats. Rohit's ninth run took his tally to 2,388 runs, which took him past Jayasuriya's 1997 tally of 2,387 runs.
Apart from ending the World Cup as the highest run-scorer, Rohit seemed to have finally found his footing in Test cricket. Opening the batting for India for the first time in the longest format of the game in the series against South Africa earlier in the year, Rohit smashed 529 runs in four innings.
"Extremely grateful for the year I've had. A World Cup victory would have been nice, but as a team, throughout the year, whether red ball or white ball cricket, we came together really well. Personally I've enjoyed batting, but there's no way I'm stopping. There's an exciting year coming up," he said.
Rohit said that the challenge will come when India starts travelling next year and they would like to stay at the top of the Test Championship table even then. India's next Test series is in New Zealand in February.
"I understand my batting really well and I want to play within my limits. Knowing the gameplan you want to execute is very important. Once we start travelling, we want to win games and stay on top of the table," he said.