Brendon McCullum underlined his status as the most feared batsman at the ICC World Twenty20 by smashing a record 123 runs off 58 balls to give New Zealand a comfortable 59-run win over Bangladesh in Pallekele.
The Black Caps had been restricted to 19 when McCullum came to the crease after 3.2 overs, but he quickly upped the pace, hitting 11 fours and seven sixes to help his team post a total of 191 for three.
Bangladesh started their reply terribly, losing their first four wickets for 37 runs and despite a half century from Nasir Hossain, they fell short of their target in making 132 for eight.
Abdur Razzak bowled Martin Guptill for 11 and restricted James Franklin at the other end to give Bangladesh a good start, but McCullum took the game by the scruff of the neck.
The 30-year-old, who moved to the top of the Twenty20 batsman rankings last week, racked up a 50 partnership with Franklin in little over five overs and reached his own half-century after just 29 balls with some aggressive strokes.
The removal of Franklin by Mashrafe Mortaza in the 15th over did not suppress McCullum as the former Sussex man swatted the medium pacer over long-off for six in the same over.
McCullum smashed 51 off the last five overs to register the biggest score in Twenty20 history, beating the previous record of 117 set by South Africa's Richard Levi.
Bangladesh got off to a terrible start in their run chase, with Tamim Iqbal cutting Kyle Mills to Guptill after three balls and the seamer snared Shakib Al Hasan in the third over to leave the Tigers on 19 for two.
Mills then dismissed Mushfiqur Rahim for four and Tim Southee trapped Mohammad Ashraful (21) lbw to leave Bangladesh four down in the seventh over.
Mahmudullah and Hossain steadied the ship with a 50 partnership but Nathan McCullum's off-spin removed the latter for 15.
Any fears of an unlikely comeback were dismissed in the 18th over when Guptill caught Hossain off Southee on the boundary.
Jacob Oram then got in on the act with a wicket and Southee added his third victim to seal an impressive win for New Zealand that leaves Bangladesh needing victory over Pakistan to stay in the tournament.