Off-spinner Ravichandran Ashwin claims 6 for 46, his best overseas figures
Captain Angelo Mathews top-scores for Sri Lanka with 64
Opener Shikhar Dhawan (batting 53) and captain Virat Kohli (batting 45) steady India after early wobble
India off-spinner Ravichandran Ashwin claimed six wickets for 46 runs in a fine display of spin bowling as India skittled out Sri Lanka for 183 in two sessions on the opening day to take the upper hand in the first Test, in Galle, on Wednesday.
In reply, the visitors lost two early wickets, but recovered well to score 128 for 2 at stumps. They trail Sri Lanka by 55 runs.
Opener Shikhar Dhawan (53) and captain Virat Kohli (45) were unbeaten, having added 100 runs for the third wicket.
Lokesh Rahul (7) and Rohit Sharma (9) were both out leg before wicket as India were reduced to 28-2. However, Dhawan, dropped on 28 by home captain Angelo Mathews off Tharindu Kaushal, and Kohli steadied the innings to keep the tourists on course for a big first innings lead.
Earlier, Mathews (64) was the top-scorer for Sri Lanka while wicketkeeper Dinesh Chandimal contributed 59 after the hosts' decision to bat in the first match of the three-Test series backfired.
Ashwin, who registered his best figures overseas, claimed his 11th five-wicket haul in Tests, while leg-spinner Amit Mishra picked up two wickets off successive balls in his return to Test cricket after four years.
The pacers gave India early breakthroughs, Ishant removing Dimuth Karunarante (9) with a short delivery, and Varun Aaron accounting for the other opener. Kaushal Silva (5), two balls later with another bouncer.
Dhawan made amends for dropping Silva in Aaron's previous over by taking a diving catch, though replays suggested the ball came off the batsman's arm guard when he attempted a hook shot.
Retiring batting stalwart Kumar Sangakkara did not last long either in his penultimate Test. He fell to Ashwin's third delivery of the morning.
The lanky off-spinner extracted enough turn and bounce from the surface to fox Sangakkara and Rahul pouched a sharp catch at silly point.
Ashwin also claimed the wickets of Lahiru Thirimanne (13) and Jehan Mubarak (zero) in successive overs as Sri Lanka slumped to 65-5 at lunch.
The hosts fought back with a 79-run stand for the sixth wicket between Mathews and Chandimal, who was dropped by wicketkeeper Wriddhiman Saha on five off Ishant.
Mathews became Ashwin's fourth victim and the spinner completed his five-wicket haul with a lbw dismissal of Dhammika Prasad.
Mishra added to Sri Lanka's woes by dismissing Chandimal and Tharindu Kaushal off successive deliveries but sent his hat-trick delivery down the leg side against Nuwan Pradeep.
Kohli, leading the side for the first time in a full series, went in with five bowlers, including three spinners while the hosts also included an extra spinner in Rangana Herath.