The 20-year-old cracked the best ever individual Test score by a Bangaldeshi when he made 158 not out but his second Test century came after three years and 22 matches since his first one on his maiden appearance against Sri Lanka three years ago.
"I had come close to making a hundred many times before but I realised I am not going to get a century in every match. I have matured now, and this hundred is a mark of thatmaturity," said Ashraful who also holds the record of being the youngest to score a century on debut at the age of 16 in 2001.
Ashraful said it was disappointing that Bangladesh could not avoid the follow on after they were bowled out for 333 in reply to India's 540.
Bangladesh suffered a familiar batting collapse in the second innings to be 118 for nine at stumps on the third day, and need 90 runs more to avoid an innings defeat.
Ashraful moved from 62 to 100 in 25 balls after lunch, his last seven scoring shots being in boundaries.
"I knew that the second new ball was 20 overs away and wanted to make the most of the old ball. So I decided to play some aggressive shots and be positive," he said.
Irfan Pathan, who claimed his third five-wicket haul in the second innings to trigger a collapse, said he was disappointed to miss out on a hat-trick once again.
Pathan, who had gone went wicketless for most part of the day, turned things around with two wickets off successive balls towards the end of home team's first innings.
"I was thinking to get one (hattrick) but bowled a bad delivery," he said.
"I think I was trying too hard in the first innings. One thing I learnt today was that I am not going to get a five-wicket haul every time I bowl in a Test match. The important thing is to bowl well. Sometimes you don't get wickets even when you bowl well."
He said captain Sourav Ganguly consulted the bowlers before enforcing the follow on.
"He always consults us, they were going to use the roller and the pitch was beginning to crack up," said the left arm pacer who bowled 14 overs on the trot.
"I felt I could go on. The ball was moving a bit, and I felt good...," he said.