Kane Williamson marked his return to the World Cup with an undefeated 78 as New Zealand cruised past Bangladesh by eight wickets on Friday but the captain was forced to retire hurt with a thumb injury.

Williamson had been sidelined with a serious knee injury picked up during the IPL and sat out New Zealand's first two wins at the World Cup.

Chasing 246 to win, the 33-year-old, playing his first ODI since January, had reached his 43rd fifty in the format off 81 balls and was looking well set for a century.

He moved on to 78 with eight fours and a six when he had to call it quits after a throw from the deep rapped him painfully on the glove, jamming his thumb against the bat handle.

In discussion with the medical team, and with the Black Caps only 46 runs short of victory, it was decided to take Williamson out of the game.

"Not sure just yet," said Williamson when asked about the gravity of the injury.

"It got a bit fat and colourful straight away which made holding the bat difficult. I'll have a scan tomorrow and hopefully it's okay."

New Zealand comfortably wrapped up their third win with 43 balls to spare.

Williamson had put on a second-wicket stand of 80 with opener Devon Conway (45) and then 108 with Daryl Mitchell who raced to his 50 off 43 balls.

Mitchell did it in some style with a giant heave for six off Bangladesh seamer Shoriful Islam.

Mitchell finished undefeated on 89 off just 67 deliveries, with six fours and four sixes under his belt.

New Zealand, runners-up at the 2015 and 2019 World Cups, had already defeated defending champions England as well as outsiders Netherlands in India.

Bangladesh defeated Afghanistan and then lost to England.

Earlier, Mushfiqur Rahim hit a fine half century to lead Bangladesh to 245-9 while veteran Black Caps fast bowler Trent Boult claimed a 200th one-day international wicket.

Mushfiqur made 66 off 75 balls with six fours and two sixes, taking his number of fifties in the format to 48 having also hit a half-century against England three days ago.

The 36-year-old, playing in his 259th ODI, shared a crucial 96-run fourth wicket partnership with skipper Shakib Al Hasan (40) to help their team recover from 56-4.

Mushfiqur was eventually clean-bowled by Matt Henry as he attempted to pick up the scoring rate after Shakib had perished, caught by wicketkeeper Tom Latham off Lockie Ferguson after top-edging an attempted pull shot.

Shakib ended his innings suffering from cramps in the sweltering heat and batting without a helmet or cap against the spinners.

After the game, teammate Najmul Hossain Shanto said Shakib "has gone for a scan" without specifying the injury concern.

"We'll then know what's happened to him," said Najmul.

Mushfiqur's brother-in-law Mahmudullah, batting at number eight, added a valuable undefeated 41.

Boult, meanwhile, became the sixth New Zealand player to take 200 ODI wickets.

The 34-year-old reached the personal landmark when he dismissed Towhid Hridoy, caught at extra cover by Mitchell Santner for 13, in the 38th over.

Playing in his 107th ODI, Boult also dismissed opener Liton Das off the first ball of the match.

Liton was celebrating his 29th birthday but any hopes of a big score to mark the occasion were shattered when he shuffled down the wicket to confront Boult only to sky the ball to a grateful Henry who pocketed the chance at fine leg.

(AFP)