Sri Lanka's Samarawickrama helps sink Bangladesh in Asia Cup
Put into bat, defending champions Sri Lanka rode Samarawickrama's 72-ball knock to post a competitive 257-9 on a slow track at the R Premadasa Stadium.
In reply, Bangladesh, beaten by Pakistan in their previous match, were all out for 236 in 48.1 overs despite Towhid Hridoy's gallant 82.
This was Sri Lanka's 13th consecutive victory in one-day internationals, a streak second only to Australia's 21 successive wins two decades ago.
Sri Lanka got off to a decent start with Kusal Mendis (50) and Pathum Nissanka (40) taking them past the 100-mark in the 22nd over.
Samarawickrama accelerated towards the end to take them past the 250-mark before falling to the final delivery of the innings.
Taskin Ahmed and Hasan Mahmud claimed three wickets apiece for Bangladesh.
The touring side began briskly with Mehidy Hasan Miraz and Mohammad Naim forging a 55-run opening stand before Sri Lanka took charge.
Home captain Dasun Shanaka (3-28) removed both openers in successive overs and Matheesha Pathirana (3-58) dealt a body blow by dismissing Bangladesh captain Shakib Al Hasan for three.
Bangladesh were alive in the contest as long as Hridoy was in the middle but Maheesh Theekshana (3-69) removed him and Taskin Ahmed in the same over to tilt the game in Sri Lanka's favour.
Pakistan meet India in a much-anticipated Super Four contest on Sunday even though rain has been forecast for the match, which has a reserve day.
