Strauss is only the 10th Englishman to score two centuries in a Test match
Andrew Strauss said the knowledge of the Chennai pitch he picked up making his first innings century helped him make another hundred in the second.
Strauss's knocks of 123 and 108 made him the first Englishman to hit tons in both innings of a Test in India.
"It was more a case of making sure I didn't go outside my bubble and do anything stupid," he told BBC Sport.
"Generally I stuck within my bubble and I knew if I did that, I'd have a good chance of scoring runs."
It was the first time Strauss had managed two centuries in a match in his career.
In so doing, he became the first Englishman to achieve a pair of centuries in a Test since Marcus Trescothick in 2004, and only the 10th Englishman to manage it.
"It's been a pretty special week for me - that second hundred meant a lot, because I've never done it before.
"I'm absolutely delighted, also because we're in great position to go on and win the match. If we do, that would make it easily the best week of my career."
England declared on 331-9, setting India 387 to win, but Virender Sehwag gave the home side a more than fighting chance with a knock of 83 off 68 balls, to leave India on 131-1 at the close.
"He's a special talent and plays shots no-one else can," said Strauss of Sehwag.
"He took the game to us and we looked under the cosh for a while, so it was great to get him out.
"There are nine wickets to go but we're pretty confident we can do that.
"The wicket is misbehaving enough for us to think there are at least nine opportunities for us so we need to take them. If we do it'll be a great victory."
Gautam Gambhir shared an opening stand of 117 with Sehwag, and he said the inroads they had made into their target gave them grounds for optimism going into the final day.
"It is a pleasure watching him bat from the non-striker's end," he said.
"My job became really easy because bowlers are on the defensive so I think the way he batted has put us on the front foot.
"All three results are possible, but we are really optimistic of chasing down that total tomorrow (Monday).
"He (Sehwag) has set the game up for us with the way he batted. The 260 that we need now is a very attainable total."