The speedster wreaks havoc taking six for 7, including a hat-trick, to help the host to a 2-1 win.
Pacers Deepak Chahar (6/7 in 3.2 overs), who registered the best figures in a T20 match on Sunday besides becoming the first Indian to take a hat-trick in the shortest format, and Shivam Dube (3/30) shared nine wickets between themselves to secure India’s first T20 series win at home this season.
Heavy late evening dew rendered the spinners ineffective but Chahar and Dube rose to the occasion.
Iyer (62 off 33) and Rahul (52 off 35) had earlier smashed sublime half-centuries to propel India to 174 for five after Bangladesh opted to field. Chasing the target, the visitor was all out for 144 in 19.2 overs. With 50 needing off the last 30 balls and six wickets in hand, Bangladesh had a great opportunity to win the series but it crumbled under pressure.
Rookier opener Mohammad Naim (81 of 48) played a blinder to take Bangladesh deep into the game before it lost five wickets for 20 runs to blow it all away.
Chasing a challenging 175, Bangladesh suffered early setbacks as Chahar had opener Liton Das and Soumya Sarkar caught off successive balls to leave the visitor at 12 for two.
Naim, playing his debut series, and Mohammad Mithun (27) shared a 98-run stand for the third wicket to bring their team back into the contest.
Left-hander Naim played some exquisite strokes especially against the spinners and welcomed Yuzvendra Chahal into the attack with three consecutive fours.
Earlier, a maiden half-century for Iyer and the sixth one for Rahul helped India put up a competitive total. Iyer’s cracking knock came after he was dropped on 0.
Bangladesh skipper Mahmudullah followed the template set in the series by winning the toss and opting to field. India made an unexpected call by dropping a bowler in Krunal Pandya for middle-order batsman Manish Pandey. The host was dealt a body blow in the second over when pacer Shafiul Islam removed their skipper Rohit Sharma, who had made a sublime 85 in the series-levelling win in Rajkot. Rohit tried to whip a length ball but only managed an inside edge on to the stumps.
Rahul joined Shikhar Dhawan (19 off 16)in the middle and with both the batsmen under pressure having not made an impact the first two games, the situation provided them an ideal platform to deliver.
Dhawan got going with successive boundaries off Al-Amin Hussain. Rahul too began his innings in a similar fashion, going for the aerial straight drive.