Debutant Jaker Ali Anik's valiant effort went in vain as Bangladesh suffered a heartbreaking three-run defeat to Sri Lanka in the three-match T20 International series opening game on Monday at Sylhet International Cricket Stadium.

Sri Lanka posted a daunting 206-3 but Jaker's bold approach in his just first International game brought Bangladesh to the closer before Dasun Shanaka denied the hosts a victory what could have been a landmark effort.

Shanaka defended 12 runs in the last over impeccably and took two wickets including Jaker as Bangladesh eventually were restricted to 203-8. Jaker who smote four fours and six sixes was dismissed after 68 off 34.

Put into bat first, Sri Lanka posted a big total, riding on three effective knocks. Sadeera Samarawickrama hit an unbeaten 61 off 48 after hitting eight fours and one six while Mendis gave a fluent start with 36 ball-59, an innings laced with six fours and three sixes.

Later stand-in captain Charith Aslanka gave the finishing touch with six-laden 44 not out off just 21 deliveries. He smote six sixes in his innings, which was instrumental in propelling the side past 200-run mark.

Bangladesh started with a bang when Shoriful Islam dismissed Avishka Fernando in the second ball of the innings. With Taskin Ahmed joining him by removing Kamindu Mendis for 19, Bangladesh left Sri Lanka at 37-2 and got a glimmer of hope to stifle them.

But the joy was short-lived as Samarawickrama and Kusal Mendis showed an unwavering resolve in thwarting Bangladesh bowling line up.

The duo added 96-run in a rapid third wicket stand to bring the side in a position of dominance, which they held on till the end.

Leg-spinner Rishad Hossain broke through with the wicket of Mendis and his dismissal brought Asalanka into the crease. He bludgeoned Bangladesh bowlers right from the words go with Samarawickrama playing a second fiddle to him.

Together they shared 72 off just 32 balls to help the side end on a high, which later proved to be decisive with dew effectively neutralizing bowlers' effort.

Bangladesh made a horrible start in reply of a big chase as they were reduced to 30-3 in fifth over with Angelo Mathews taking two before finishing with 2-17 in three overs.

When fast bowler Matheesha Pathirana dismissed captain Najmul Hossain Shanto who made 20 off 22, Bangladesh's hopes looked faded away with the side at 68-4.

Veteran Mahmudullah, playing his first T20 match in two years, counterattacked to bring the side back in the contest. He and Jaker added 47 runs for the fifth wicket before Maheesh Theekshana got the better of Mahmudullah after he scored 54 off 31 with two fours and four sixes.

Jaker, who was initially shaky, then played the anchor to keep the side going. He single-handedly took the side to the closer before Shanaka's brilliance denied Bangladesh the victory.

The second match is on Wednesday.