With this win, Sri Lanka opens their account in World Cup Super League with 10 points.
Mushfiqur Rahim became only the 4th player to smash 6000 runs in ODIs as wicket-keeper while Shakib Al Hasan became the joint leading wicket-taker for Bangladesh in ODIs.
The 29-year-old put Sri Lanka on top with his lethal fast bowling on Tuesday.
Not only did the home side lose two wickets, but they also lost both their reviews in consecutive deliveries.
The series was thrown into jeopardy on Sunday morning when three members from Sri Lanka's contingent tested positive for Covid-19 in Dhaka.
Bangladesh can be hopeful of giving tough competition, considering the recent form of depleted Lankan team.
Subscribe To Our Daily Newsletter And Get News Delivered Straight To Your Inbox.