Ban 253-4published at 46.1 overs
Four more! Shakib punches Boult down the ground to the rope.
Shakib & Mahmudullah share record 224-run partnership
They combined with Bangladesh at 33-4
Both men complete centuries
NZ fell from 152-2 in 30th over to 265-8
Mosaddek took 3-13, Taskin 2-43
Taylor top-scored with 63, Williamson 57
Highlights on BBC Two at 23:50 BST (UK only)
Phil Dawkes, Marc Higginson and Amy Lofthouse
Four more! Shakib punches Boult down the ground to the rope.
Charles Dagnall
BBC Test Match Special
This is incredible from these two....
Athar Ali Khan
Former Bangladesh all-rounder on BBC Test Match Special
Sensational, absolutely brilliant! What an innings, Shakib has been at his best. He's not been in form so what a time to come back into form.
17 needed from 24 balls
A last-ball single means Mahmudullah will have to wait for the chance of his own century.
Ban 248-4
Take a bow Shakib al Hasan. Magnificent. Just magnificent. After he and Mahmudullah each move to 99, the former top-edges a pull over the keeper for six. Not a bad way to bring up what has been a truly stunning century.
Athar Ali Khan
Former Bangladesh all-rounder on BBC Test Match Special
I'm pleased to see the way these two batsmen are still at the crease looking so calm. Who would have thought they could do this when they came together at 33-4?
Scott Read
BBC Test Match Special commentator
This must be the best partnership in Bangladesh's one-day history.
tms@bbc.co.uk
Still time for Shakib and Mahmudullah to reach three figures each. What a fantastic day for Bangladeshi cricket! And what an incredible tournament so far! Bravo!
Alex Meissner
26 needed from 30 balls
These two are matching each other shot for shot, run for run. They trade a couple of singles before Shakib clubs one down the ground for four.
The partnership is worth 207 now. Both batsmen have 98. Awesome.
34 needed from 36 balls
Considering the way this game has developed over the course of this innings, this is one of THE great ODI partnerships. Neesham returns in hope of ending it but Mahmudullah is seeing it like a beach ball now. He plays a brilliant steer shot to a short ball to send it over the keeper for four. Subtly superb.
Here is one of his more brutal shots this innings...
Ebony Rainford-Brent
Ex-England batter on BBC Test Match Special
That was a superb piece of fielding from Southee - he threw it between his legs. He must have added yoga to his training schedule.
41 needed from 42 balls
New Zealand are falling apart! Southee, who was the very epitome of accuracy at the start of this run chase, sends both of his first two balls wide. That is 17 now for the innings!
Hearts are in mouths for a moment when Southee directly hits the stumps with a superb little throw through his own legs, but Shakib was home.
Salt is poured into the wound when a short ball is cut for four by Shakib right through the hands of Guptill.
#bbccricket
Sho Rahman: Come on Bangladesh! Hold it together!
51 needed off 48 balls
The Bangladesh fans are dancing in the stands now. They sense they've broken the Kiwis. Mahmudullah dances down and launches Santner down the ground for four. The bowler is thrown out of his rhythm as a big wide illustrates next ball.
A couple of well-run twos, a single and a cut shot that falls short of point makes it another good over for the chasing side.
This partnership is now worth 182 - the highest for Bangladesh for any wicket in ODI. It is all about timing, and these two have saved their best for the perfect moment.
Everything is coming up Bangladesh now...
Dan Norcross
BBC Test Match Special
It's pretty much entirely Bangladesh fans here in Cardiff today. It's all going tremendously well for them. They need not panic - but I know they are.
61 needed from 54 balls
When I left you after the 20th over, New Zealand were favourites to win this. Returning 20 overs later, I can't see Bangladesh losing it. Remarkable turnaround.
Williamson turns to his top man, Southee, to try and change that. He can't though. Shakib absolutely wallops one through cover for four to take his side past 200. Victory is in sight.
What now New Zealand?
Target 266
The Bangladesh supporters are growing in volume. They are massive favorites now, you feel. Here's Phil Dawkes to see this game to its conclusion.