Bangladesh 158 for 4 (Shanto 51, Shakib 34*) beat England 156 for 6 (Buttler 67, Hasan 2-26) by six wickets
Chattogram: Bangladesh beat world champions England comfortably by six wickets in the first T20 international in Chattogram.
Opener Najmul Hossain Shanto struck an impressive 51 from 30 balls as the Tigers reached their target of 157 with two overs to spare.
Shanto added 65 for the third wicket with debutant Towhid Hridoy, who made 24, as the hosts adapted better to a slow, sluggish pitch.
The second of three T20s takes place on Sunday in Mirpur.
It is Bangladesh's first win over England in a T20, though it is only the second time the teams have met in the format.
England were on course for a huge total as captain Jos Buttler and Phil Salt raced to 80 after 10 overs, but Bangladesh's seamers fought back at the end, conceding just 21 runs from the final four overs to restrict England to 156-6.
Buttler made a dynamic 67 from 42 balls after being dropped by Shakib Al Hasan on 19, but when he and Ben Duckett fell in consecutive balls, England struggled to make the most of their aggressive start.
Seamer Hasan Mahmud led the attack with 2-26 from his four overs, including the key scalp of Buttler.
In reply, Bangladesh also made the most of the six-over powerplay to attack England's seamers, reaching 54-2.
England's seamers struggled to adapt to the slow pitch and Shanto capitalised, striking four consecutive boundaries from Mark Wood's first over.
Captain Shakib then calmly used his experience to steer his side to victory and finish unbeaten on 34.