Earlier, centuries from Cheteshwar Pujara and Ajinkya Rahane and blistering half-centuries from Ravindra Jadeja, Ravichandran Ashwin, and wicketkeeper Wriddhiman Saha helped India post a monstrous first inning score on Day Two.
Saha then joined Ashwin in the middle, and the duo put on 29 runs for the sixth wicket without any trouble, as India progressed towards another tall first innings' score.
Dismissing Dimuth Karunaratne (25) and Upul Tharanga (0), India's R Ashwin gave a flawless start to the innings. The 29-year-old put together a 217-run stand with one-down batsman Cheteshwara Pujara (133) to help India reach a mammoth 622/9 when skipper Virat Kohli made a decision to declare.
The entertaining Ashwin (54) played some expansive shots and brought up his half-century with a swagger by launching Rangana Herath for six over long-off after lunch, but the spinner responded by cleaning him up with the next ball. Dimuth Karunaratne was Ashwin's second victim as he was caught at lone slip further sliding the home side.
Debutant left-arm spinner Malinda Pushpakumara picked up two wickets.
Mentioning about Ashwin's ability to bowl variations, he said that he was able to turn the ball quite efficiently. Rahul, who laid low in the first Test with viral fever, has now recovered and if he is successful in proving his fitness for this Test, the toss-up will be between Dhawan and Mukund for the second opener's slot.
Sri Lankan bowlers found it very hard to bowl against Indian class batsmen and also failed to put any kind of pressure on them.
Mohammed Shami chipped in with 19 runs, while Jadeja ended up making 70 not out, which came off 85 deliveries and included four boundaries and three sixes, before India declared on 622/9, which is the third-largest total made by a visiting team in Sri Lanka. While the one in Galle remained flat on all four days, this wicket is expected to aid the slower bowlers more and more as time passes on.
Ashwin had two for 38 in 10 overs.
Ajinkya Rahane scored his 9th Test Century in Colombo.
"I started my career as a bowler, not as a batsman, so I can bowl", said Karunaratne, who took his maiden Test wicket.India, who lead the three-match series 1-0, need a win to clinch the series.