Chasing a target of 155, the Lankan batsmen displayed a confident run chase, reaching the required total in just 19 overs. Veteran batter Kusal Mendis led the charge with a brilliant 73 off 51 deliveries, marking his 16th T20I half-century.
Earlier in the evening, Sri Lankan bowlers put on an impressive display to restrict Bangladesh to 154/5 in their allotted 20 overs. Despite a brisk start by Bangladeshi opener Parvez Hossain, the visitors failed to maintain momentum through the middle overs.
With this win, Sri Lanka takes a 1-0 lead in the three-match series. The second T20I will be played at the same venue on July 12.