Pace bowler Mohammed Siraj returned figures of 6-21 to lead India's rout of Sri Lanka by 10 wickets as they clinched their eighth Asia Cup title on Sunday.

Siraj got four wickets in one over to help skittle Sri Lanka out for 50, a total the Indian openers Ishan Kishan and Shubman Gill surpassed in 6.1 overs for an impressive victory ahead of next month's ODI World Cup at home.

Sri Lanka's miserably low total in the 50-over contest left a nearly packed house disappointed after they witnessed just 116 minutes of play.

The hosts elected to bat first following a delayed start due to rain and pace spearhead Jasprit Bumrah struck first with the wicket of Kusal Perera, caught behind for a duck in the first over.

Siraj soon took over as he made the ball swing and seam in overcast conditions to easily surpass his previous ODI best of 4-32.

He got Pathum Nissanka for two and then struck on successive balls to send back Sadeera Samarawickrama (0) and Charith Asalanka (0), but a hat-trick was averted.

Dhananjaya de Silva hit a boundary but Siraj had him caught behind with the next ball, much to the delight of the Indian fans.

Siraj got his fifth with the wicket of Sri Lankan captain Dasun Shanaka, equalling an ODI record for the fastest five-wicket haul from his first 16 balls of the match.

Kusal Mendis hit three boundaries before becoming Siraj's sixth wicket, although Sri Lanka avoided the lowest-ever ODI total of 35 by Zimbabwe.

After Virat Kohli's overthrow went for a boundary, and six more runs to the total, Sri Lanka pushed past their lowest ODI total of 43 scored against South Africa in 2012.

Hardik Pandya took three wickets to wrap up the innings in just 90 minutes.

Mendis' 17 and an unbeaten 13 by Dushan Hemantha were the only double-digit scores in an innings that featured five ducks.

Shubman Gill, a centurion in the previous match, began with a boundary in the opening over on his way to an unbeaten 27 and fellow opener Ishan Kishan (23) soon joined the party.

The left-handed Ishan smashed fast bowler Matheesha Pathirana for two successive boundaries, and three more in a row from Gill gave India victory in the tournament's shortest final.

Rohit Sharma's India dropped just one match in the tournament after they lost an inconsequential Super Four contest against Bangladesh.

Sri Lanka, who won the previous edition of the Asia Cup played in the T20 format, came in as underdogs and snuck into the Super Fours with a dramatic win over Afghanistan but went down without a fight in their 11th final.