Overnight batsman Dimuth Karunaratne hit an unbeaten century to keep up Sri Lanka's fight during their follow-on against India on day four of the second Test in Colombo on Sunday.

The hosts were 302-4 at lunch, still requiring 137 runs to avoid an innings defeat. Opener Karunaratne, on 136, and former captain Angelo Mathews, on 28, were at the crease.

Sri Lanka, who resumed on 209-2, lost two wickets in the morning session, including skipper Dinesh Chandimal for two. The batsman edged a catch to slip off left-arm spinner Ravindra Jadeja.

Nightwatchman Malinda Pushpakumara was the first to go on Sunday after being bowled off spinner Ravichandran Ashwin while attempting an audacious reverse sweep. He scored 16 runs.

Karunaratne, who started the day on 92, and Mathews then put together 61 runs for the fifth wicket by lunch, prompting skipper Virat Kohli to rotate his bowling options.

However, the highlight of the innings so far has been Saturday's 191-run second-wicket stand between Kusal Mendis, who fell for 110 before stumps on day three, and Karunaratne.

Sri Lanka earlier handed India the advantage after being dismissed for 183 in response to the visitors' first innings total of 622-9 declared.

India, who lead the three-match series 1-0, are looking to seal the rubber. Sri Lanka require at least a draw to stay alive.