At the end of the day's play, Mathews said he had been trying to keep the scoreboard moving during that passage of play, but could have avoided playing that shot.
"I don't think there was lapse of concentration. I was looking to score runs," he said. "It's just that it stopped a little bit, but no excuse. I should have left it alone, maybe.
"I was looking to score runs. You can't hang in there forever. On this wicket you will get a good ball and you tend to get out. All in all it's about runs. You have got to score runs. It won't be pretty. You can't be fluent on this wicket. You have got to grind and try and score runs."
Mathews added 99 for the third wicket with Lahiru Thirimanne to move Sri Lanka to 133 for 2, but both fell soon after getting to their half-centuries to bring India back into the contest. They faced some difficult spells from Bhuvneshwar Kumar, Mohammed Shami and Umesh Yadav, and Mathews called all three of them "world class".
"They keep coming at you," he said. "You can't relax. If you see, the loose balls were very few. As I said, they are top-class bowlers. Credit to Thirimanne for the way he played. But 50s won't take us anywhere. We need to try and score hundreds on this wicket."
Injuries have dogged Mathews right through the last year or so, and he felt this was a sign that the non-stop cricket he had played in the three previous years had caught up with him.
"It has been a quite a frustrating year for me with injuries, going in and out of the side," he said. "It's not easy, you know, when you don't have the same rhythm. I had a good three years of cricket from 2013 onwards; I guess it's taking a toll on my body.
"I have to manage my workload. It comes with experience as well. I have played a few more games than the rest of the boys. You have got to prepare mentally but you know it is not going to be easy here. India is a fantastic team and you have to be on the top of the game to compete against them."
Mathews has also given up captaincy and - for now, given all his fitness issues - bowling. Having endured a lean run with the bat in recent times, Mathews said he would need to raise his game to keep pulling his weight as a specialist batsman.
"I can't be thinking of me being the premier batsman and former captain," he said. "All are equal. We have to go out there and take responsibility and try and score as many runs as possible. Fifties are not going to do any good to anyone. Not for me and not for my team.
"If we get a start we need to go on to get a big one. It was a challenging wicket. All three fast bowlers bowled well. It comes with experience as well. I have played 70-odd Test matches and with experience you get to know how to get about things."