The victory came at a moment when hardly anyone put a bet on Bangladeshfollowing their sub-standard performance ahead of the global event.
It was Bangladesh's only second victory over higher ranked team in their T20World Cup history since their win against West Indies in the inauguraledition in 2007, reports BSS.
Bangladesh captain Najmul Hossain Shanto won the all important toss andexpectedly put Sri Lanka into bat first. The bowlers justified the decisionright by restricting Sri Lanka to a below par 124-9 and then overhauled thetarget with 125-8 in 19 overs by overcoming a massive adrenaline pumpingmoment. Pacer Mustafizur Rahman (3-17) and leg-spinner Rishad Hossain (3-22) claimedthree wickets apiece while fast bowler Taskin Ahmed, who is playing his firstgame after recovering from the injury grabbed 2-25. Another pacer TanzimHasan Sakib took 1-24.
While it looked the bowlers were key behind the victory, it was Towhid Hridoywhose 20 ball-40 made all difference in the low-scoring affair.
Later, Mahmudullah Riyad finished the things off with cool head when SriLanka looked all over on Bangladesh by taking some quick wickets.
Bangladesh made a disastrous start with Soumya Sarkar getting second-ball-duck as he top-edged a Dhananjaya de Silva delivery to Wanindu Hasaranga atmid-on.
Fast bowler Nuwan Thushara who snapped up 4-18 dealt a double strike, takingout Tanzid Hasan Tamim for 3 and extending skipper Shanto's lean patch bydismissing him for 7.
Liton Das and Towhid Hridoy put on a 63-run for the fourth wicket whicheventually became key behind Bangladesh's victory.
Hridoy hit one four and four sixes in his knock. He was dismissed byHasanranga after hitting him three consecutive sixes.
Hasaranga also took the wicket of Liton Das who made 36 of 38. Thushara thencame back with fire to take two wickets in consecutive deliveries beforeMatheesha Pathirana undid Shakib Al Hasan for 8.
As it looked Bangladesh's victory was in jeopardized state, Mahmudullahreleased the pressure by hitting Dasun Shanaka six with his side needing 11from 12 balls with two wickets at hands.
However, Mahmudllah completed the victory in that penultimate over by holdinghis nerve well.
Earlier, Bangladesh bowlers put a disciplined bowling effort to keep the sideon the course of a victory.
Sri Lanka made a fluent start with Pathum Nissanka tearing apart Bangladeshbowlers in a sensational batting.
Nissanka made team-best 47 off 28 with seven fours and one six.
However, Taskin Ahmed broke through with the wicket of Kusal Mendis (10) whostruck him consecutive two boundaries.
The introduction of Mustafizur brought Bangladesh back to the game as he gotthe rid of Kamindu Mendis (4) and Nissanka in his consecutive overs.
With Dhananjaya de Silva and Charith Asalanka giving Sri Lanka the ray ofhope to regroup, Rishad dismantled them in a career-best bowling effort thatsaw him taking three wickets for just 22 runs.
Dhananjaya made 21 while Asalanka contributed 19.
Sri Lanka could never recover from the collapse as they lost wickets incluster to be bowled out for a below par total.
This was Sri Lanka's second consecutive defeat following its six-wicket lossSouth Africa and it left their Super 8 hopes at peril.