Bangladesh leg-spinner Rishad Hossain took 3/22 on Friday to help restrict Sri Lanka to 124 for nine in their Group D match in Dallas and propel his team to a two-wicket victory in a thrilling start to their Twenty20 World Cup campaign.
In reply, Bangladesh reached 125/8 with Towhid Hridoy top scoring with 40 from 20 balls to win with an over to spare.
Fast bowler Nuwan Thushara took two late wickets to leave Bangladesh still to get 12 runs to go with only two wickets remaining, but the seasoned Mahmudullah (16 not out) steered his team to victory from the last ball of the 19th over. It was Lanka's second successive loss and makes their Super Eight qualification tougher.
"Everybody's body language was great, we gave 130%," said Bangladesh captain Najmul Hossain Shanto.
"I think they bowled really well but on a wicket like this we should have won this easily."
Hossain, who was named player of the match, had an opportunity to secure a hat-trick after taking wickets with consecutive balls but could not capture the final wicket.
"I tried my best. I tried to bowl it as normal," he said.