This was Bangladesh’s sixth consecutive win over New Zealand, following a 4-0 victory in 2010 in Bangladesh.
Set a target of 248, New Zealand caved in for 207 in 46.4 overs on Thursday (October 31) in Mirpur. Bangladesh had already won Tuesday's series opener by 43 runs.
Sohag Gazi, the offspinner, and Mashrafe Mortaza, the veteran right-arm pacer, led Bangladesh's bowling attack, sharing six wickets between them to stifle New Zealand. Gazi had earlier contributed a 24-ball 26 from No. 8 to help his side post a competitive total.
Mortaza struck early, bowling Hamish Rutherford for 1 and Gazi took a return catch off Anton Devcich, the other opener. When Abdur Razzak then trapped Grant Elliot in front, New Zealand was reeling at 45 for 3.
Corey Anderson (37) and Ross Taylor tried to rebuild, but a stunning catch by Mushfiqur Rahim, the captain, off Mortaza ended the 61-run stand and sent Anderson on his way, giving Bangladesh a firm grip on the match.
Bangladesh sensed victory when Mominul Haque, the left-arm spinner, had Brendon McCullum, the New Zealand captain, out lbw for 14. Taylor, who scored 45, held down one end before he was caught by Mahmudullah off Gazi at long-on.
Some late blows by Nathan McCullum, who scored 25 off 23 balls, and Kyle Mills who remained unbeaten on 27 off 25 balls, only delayed the inevitable.
Earlier, Anderson and James Neesham grabbed four wickets each as New Zealand bowled Bangladesh out for 247 in 49 overs on a slow Shere Bangla pitch. Anderson finished with 4 for 40 while Neesham claimed 4 for 53, his second successive four-wicket haul in the series.
Tamim compiled a patient half-century but was out just when Bangladesh was looking for him to accelerate. He hit 58 off 86 balls, which included five fours and a six, and overtook Shakib Al Hasan during his innings to become Bangladesh’s leading scorer in ODIs.
Tamim, who has now 3702 runs in 124 ODIs, put on 63 with Shamsur Rahman, the debutant, in the opening stand after Mushfiqur won the toss and elected to bat.
Shamsur, replacing Anamul Haque in the line-up, managed only 25 before he fell to Nathan McCullum. Bangladesh went into the batting powerplay in the 36th over on 149 for 3, but then lost three wickets in three consecutive overs and couldn’t capitalise on the field restrictions. Mominul Haque (31) and Mushfiqur (31) were the other notable scorers for Bangladesh.
The third and final match of the series will be held on Sunday at Fatullah.