Virat Kohli after ton against Proteas: I've never been a big believer of a lot of preparation

The 37-year-old struck 135 off 120 balls to help India beat the tourists by 17 runs in the opening game of the three-match series.

The innings was remarkable because Kohli had not played any competitive cricket for more than a month as he has retired from T20I and the Test formats.

He said: "I've never been a big believer of a lot of preparation. All my cricket has been mental.

"As long as I feel mentally I can play the game, I work physically very hard every day of my life it's got nothing to do with cricket anymore, it's just the way I live.

"So as long as my fitness levels are up and my enjoyment and mental sharpness is there, then you can visualise the game and you see yourself running as hard, reacting fast on the ball, then you know it's fine.

"(I know) one of the days when the game opens up and you get a start, you'll be able to score some runs."

It was his 306th appearance in the 50-over format for his country and all Kohl used all that experience to assess conditions.

He added: "If you play 300-odd ODI games and so much cricket over the last 15-16 years, as I said if you're in touch with the game and you know that when you're hitting balls at practice, your reflexes are there, your physical ability is there to bat long, if you can bat an hour and half to two hours in the nets without taking a break, you're kind of meeting all those markers.

"I understand if there's a dip in form, you look for games and you try to get that form back. But as long as you're hitting the ball well and you're playing good cricket, I think at this stage with the experience that I have for me, it's about being physically fit, mentally ready and excited to play the games that I'm playing, and more or less everything else should take care of itself."

The second ODI of the series takes place in Raipur on Wednesday.