Pakistan endured a battering by New Zealand's top-order before launching their own onslaught through centurion Fakhar Zaman to win a rain-hit World Cup game by 21 runs via the DLS method on Saturday and stay alive in the hunt for a semifinal spot.

Chasing 402 to win the high-stakes clash, Pakistan took the attack to New Zealand as Fakhar hit a blistering century off 63 balls and Babar Azam inched towards his fifty when rain halted play with the score on 160-1 in 21.3 overs.

The target was revised to 342 in 41 overs and Fakhar picked up from where he left off, reaching 126 not out with eight fours and 11 sixes, while Babar struck an unbeaten 66 but the showers returned with Pakistan adding 40 to their total in four overs.

Pakistan's fireworks meant they were 21 runs ahead of the DLS par score when the game was eventually called off, ensuring a victory that took them to eight points from as many matches - level on points with fourth-placed New Zealand.

Earlier, Rachin Ravindra smashed his third ton of the World Cup while a fit-again Kane Williamson made up for lost time with a 95 as New Zealand posted a commanding 401-6 from 50 overs.

Ravindra, who was born in Wellington to Indian parents from Bengaluru, delighted the local fans with measured strokeplay and provided moments of magic to go past 500 runs in the World Cup with a 94-ball 108 that included 15 fours and a six.

The 23-year-old stitched together a 180-run partnership with captain Williamson while Daryl Mitchell (29), Mark Chapman (39), Glenn Phillips (41) and Mitchell Santner (26 not out) fired to swell the New Zealand total to 401-6 in 50 overs.

Babar's decision to bowl first after winning the toss had raised some eyebrows as New Zealand made a fiery start at the M Chinnaswamy Stadium, with opening batsmen Devon Conway and Ravindra dominating the powerplay.

Hasan Ali, who replaced Usama Mir to give the 1992 champions an extra pace option, had Conway caught behind for 35 to end the pair's 68-run stand and bring Williamson to the wicket.

Playing his first match since sustaining a fractured thumb against Bangladesh last month, Williamson toyed with the bowlers and provided the perfect foil to Ravindra before cutting loose, having made his second half-century of the tournament.

Williamson fell to Iftikhar Ahmed while going for his third six, before Ravindra was dismissed by Mohammad Wasim (3-60), but 2019 runners-up New Zealand would heap more misery on Pakistan, only to suffer disappointment later.