Skipper Kane Williamson struck a composed unbeaten century as New Zealand virtually knocked South Africa out of the World Cup with a four-wicket victory in a last over finish in Birmingham on Wednesday.

Chasing a target of 242 in 49 overs in rain-truncated match, New Zealand recovered from a mini slump at 137/5 riding on a 91-run stand between Williamson (103 not out off 138 balls) and Collin de Grandhomme (60 off 47 balls) to reach home with three balls to spare.

Needing 12 off last seven balls, Williamson steered a Lungi Ngidi slower delivery to third man boundary to bring down the equation to 8 off the last over.

With Ngidi (1/47), Kagiso Rabada (1/42) and Chris Morris (3/49) all bowling their full quota, Faf Du Plessis had no option but to use their weakest link Andile Phehlukwayo.

Williamson promptly hit the second delivery for his first six of the match to close the encounter.

With this win, New Zealand went top of points table with nine points from five games while South Africa after their fourth defeat in six games have little chance of making it to the last four.

Williamson’s innings had eight fours and a six, while De Grandhomme was the aggressor during the stand with five fours and two sixes.

The Black Caps’ skipper was on 76 when he got a faint edge to a ball by leg-spinner Imran Tahir that Quinton de Kock took behind the stumps but South Africa took no action.

That decision could prove fatal to their tournament hopes, with the Proteas now needing a miracle to progress to the semi-finals after just one win from six matches, while New Zealand now top the 10-team table.

Earlier, Martin Guptill, who had been guiding New Zealand towards their target of 242 off a rain-reduced 49 overs with a minimum of fuss, trod on his stumps to spark a mini collapse.

The batsman, on 35, pulled Phehlukwayo and ended up swivelling, only to lose his balance and clip his leg stump with his foot.

Two overs later New Zealand slipped to 74/3 when Ross Taylor tickled a Chris Morris leg-side delivery and De Kock took the catch behind the stumps. Tom Latham’s dismissal left them struggling at 80/4.

Jimmy Neesham (23) steadied the ship with his skipper but when he was out, New Zealand were back in trouble at 137-5.

Colin de Grandhomme came to New Zealand’s rescue, batting positively and bringing up his fifty off 39 balls but when he was caught in the deep for 60 by Du Plessis off Lungi Ngidi, Kiwi nerves were jangling again.

Eight were still needed off the final over.

But Mitchell Santner pinched a single and Williamson kept his nerve, bringing up his century with a huge six off the next ball and then a four sealed the victory.

Earlier, Rassie van der Dussen gave South Africa something to bowl at as the Proteas struggled to 241-6 after losing the toss.

Hashim Amla made a sluggish 55 off 83 balls but Van der Dussen’s 67 not out came at better than a run a ball.

During his innings, Amla became the fourth South African to reach 8,000 runs in one-day internationals.

He is the second-fastest player (176 innings) from any side to reach the milestone after India’s Virat Kohli (175 innings).

(With AFP and PTI inputs)