In the last two overs, Bangladesh needed 22 runs. Mushfiqur smashed Khaleel Ahmed for four consecutive fours in the 19th overs and almost sealed the game for the Tigers.
In the last over, Bangladesh needed 4 runs. Mahmudullah scored two runs in first two balls and the next delivery was wide. In the third ball, Mahmudullah hit a big six over the midwicket to register the first win in T20Is against India.
Mushfqiur remained unbeaten on 60 off 43 balls with eight fours and one six while Mahmdullah remained unbeaten for 15 off seven with one four and one six. Bangladesh ended on 154 for three in 19.3 overs and won the game by seven wickets.
Earlier, Bangladesh won the toss and sent India to bat first. They scored 148 for six in 20 overs. In reply, Bangladesh lost Liton Das early. The right-hander drove Deepak Chahar to cover where Lokesh Rahul took a simple catch to remove him for seven.
However, debutant Mohammad Naim and Soumya Sarkar came with a strong reply in the second wicket stand. They added 46 runs, which helped the touring side get a good foundation.
Naim fell for 26 off 28 with two fours and one six. After playing four consecutive dot balls, Naim skied a ball of Yuzvendra Chahal. Shikhar Dhawan took an easy catch to dismiss him.
Bangladesh scored 62 at the end of 10 overs. At the end of 15 overs, Bangladesh were 99 for two.
They needed 50 runs in the last overs. With Mushfiqur Rahim and Soumya in the wicket, it was achievable. At the same time, Bangladesh had eight wickets in hand.
But Soumya fell at the end of 16th over. He was bowled out by Khaleel Ahmed at 39 off 35 with one four and two sixes.
Earlier, Shikhar Dhawan guided India to score 148 runs. He was the best batsman for India scoring 41 off 42 deliveries with three fours and one six.
India started well as Rohit Sharma flicked Shafiul Islam for a four off the first delivery of the match. But Bangladesh turned it to their side at the end of the first over when Shafiul trapped Rohit for nine off five balls. Rohit was adjudged lbw after he missed the slower ball seaming in.
India posted 35 in the powerplay losing the wicket of Rohit only. But in the seventh over, Mahmudullah handed over the ball to Aminul Islam Biplob who removed Lokesh Rahul in his first over.
Aminul delivered a slow ball and Lokesh came back before playing a soft shot. Mahmudllah took a regular catch at short cover.
Despite losing two wickets in seven overs, India never looked in trouble because of Shikhar Dhawan. The southpaw was scoring slowly but was a big trouble for the Tigers. However, he fell for 41 during the 15th over in a run-effort by Mahmudullah and Mushfiqur Rahim.
Before Dhawan, Shreyas Iyer scored 22 off 13 balls. His short-term but effective innings was ended by Aminul.
At the end of 15 overs, India were 95 for four. In the last five overs, they amassed 53. Bangladeshi bowlers were most expensive in the last three overs when the conceded 38 runs.
In the seventh-wicket stand, Washington Sundar and Krunal Pandya added 28 runs just in 10 balls.
Eventually, Bangladeshi bowling attack restricted India in 148 for six in 20 overs.
Teenager leg-spinner Aminul was the best bowler of Bangladesh taking two wickets conceding 22 runs in 3 overs. Shafiul also bagged two wickets but he spent 36 runs in four overs. Afif Hossain took one wicket.
The remaining games of the series will be played on November 7 and 10 respectively in Rajkot and Nagpur. After that, both teams will lock horns in two Tests in Indore and Kolkata. The last match of the series, the Kolkata Test, will be the first day-night Test for both teams.