Opening the innings, Rahul scored a composed 158 on day two to help India finish at 358/5, a lead of 162 runs with still three days to go.
It was the highest individual score for Rahul, who had notched up his maiden ODI hundred on debut in Zimbabwe. This is his third Test ton overall and all three of them have come outside India Australia, Sri Lanka and now in the Caribbean.
Even so, his place in the eleven is not confirmed yet, as he was a replacement for the injured Murali Vijay. That could change in the near future.
"To me, it didn't look too difficult. I went in there and started hitting the ball from the first or second ball.
Obviously, I've been spending a lot of time in the nets. It's a different challenge once you go out there and when you have the pressure of the game," Rahul said after the end of the second day's play.
"I tried to keep things simple. I've been in good form for the last 3-4 months. I've been moving well, and hitting the ball really well.
"My plan when I went out yesterday was to put the loose balls away and be positive and have a very aggressive intent.
I am really happy with the way I batted. I don't know whether it is easy or tough, but the simplest things if you do it right, it pays off all the time.
"That is to play to the merit of the ball, you think the ball is there to be hit, and you feel confident, then you hit the ball. I tried to keep it simple," he added.
The 24-year-old from Karnataka said he is enjoying his consistent run in all three formats of the game.
"The last couple of months, I've been performing well.
I've been consistent in all the three formats and that's what I want to do as a cricketer," said Rahul.
"I'm only watching the ball and trying to judge the ball and if I think the ball is there to be hit, I'm hitting the ball. I'm very happy with the space I'm in and the focus levels have been great.
"The biggest challenge was obviously the weather, it was a very hot day. When I went into bat yesterday, the wicket was still a little two-paced and a little damp, and the ball was doing a little bit.
"Those were the challenges but once I got a few runs under my belt, and once I spent a little time on the wicket, I felt comfortable. To have Virat Kohli, R Ashwin and the other guys speak highly of me definitely gives confidence.