Siriwardena's World Cup best and Achini Kulasuriya's 2/19 saw Bangladesh slip up in their final match of the tournament as they could manage just 91 runs in their allotted 20 overs at the Junction Oval.
The win for New Zealand means Group A is perfectly set-up for a final showdown, with a Trans-Tasman match on Monday seeing them face Australia, with the winner set to reach the semifinals.
If this was not enough to boast, the 83 scored by Healy against Bangladesh is the most in an innings by a keeper at the mega event.
Healy scored 83 off 53 with the help of ten fours and three sixes, whereas Mooney scored 81 not out off 58 which was laced with 9 fours. The duo stitched an opening-wicket partnership of 151 runs and took the match far away from Bangladesh.
"We are gonna have bat today. It's generally a good batting wicket here and gives us a chance to start well with the bat," said Lanning after winning the toss.
