England looked to have set a strong total as captain Jos Buttler (94 not out) and Harry Brook (80) led the tourists to 342-7 after Bavuma had put them in to bat in Bloemfontein.

However, the Proteas skipper led from the front with 109 from 102 balls, as South Africa kept up with the required rate throughout, before David Miller (58 not out) and Marco Jansen (32 not out) saw them home with five balls to spare after an unbroken stand of 65.

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The victory gives South Africa an unassailable 2-0 lead ahead of Wednesday's series finale, and provides a further boost to their hopes of securing automatic qualification for the World Cup later this year in India.

The Proteas, who are currently ranked outside the top eight 50-over sides that will qualify for the World Cup, must beat England on Wednesday and win both games in their two-match series against the Netherlands in March and April to move into an automatic qualifying position.

With England seeking to end a run of five successive ODI defeats, there remains plenty to play for in Kimberley, live on Sky Sports, where Jofra Archer could continue his return from injury having been rested on Sunday.

Brook, Buttler help England recover from slow start

England's start with the bat was in complete contrast to their run chase on Friday, when they gave up a hugely strong position to lose after a 146-run opening stand from Jason Roy and Dawid Malan.

This time they were troubled from the start by Wayne Parnell (1-54) and the recalled Lungi Ngidi (1-66), who benefitted from a pitch that offered help to the bowlers first thing in the morning, as their skipper had predicted it would at the toss.

Roy needed a DRS review to survive when the ball was shown to be going over the stumps after he had been given out lbw to Parnell, but his reprieve was only brief as he was clean bowled an over later by a brilliant Ngidi in-swinger.

Malan's wicket followed in the next over as he was trapped plumb lbw by Parnell, leaving the less experienced duo of Ben Duckett and Brook, fresh off a duck on his ODI debut on Friday, facing a challenging situation.

The pair saw off the openers as England ended the opening 10-over powerplay on 42-2, and then did well to resist South Africa's impressive first change options Jansen (1-66) and Anrich Nortje (2-64).

Brook eventually got onto the front foot, following up a fortuitous first boundary with a glorious shot through the off-side for another, which would be a sign of things to come.

Duckett undid the hard work he had put in to see off the seam onslaught when he holed out to long-off during spinner Keshav Maharaj's first over, leaving England in a vulnerable position at 82-3.

Undeterred by South Africa's strong start, Brook continued to attack, racing to a half-century from 46 balls, and continuing to attack as he reached 80 from 75 balls.

With Buttler going along nicely at the other end, South Africa looked bereft of ideas as Bavuma spurned his side's second and final review on a hopeless lbw shout against the England captain.

However, Brook would let the hosts off the hook, hitting South Africa's secondary spin option Markram straight to Rassie van der Dussen off the off-side boundary.

Buttler appeared to see Brook's dismissal as his cue to kick on and brought up his own half-century from 49 balls, as he and Moeen Ali began to put pressure on the home side, taking England past 200 in the 36th over.

Moeen took centre stage with some meaty blows of his own, before dragging on a Nortje delivery to fall for 51 from 45 balls.

Buttler was starved of strike as Chris Woakes could only manage a frustrating 14 from 16, but his dismissal paved the way for a grandstand finish.

Sam Curran (28 from 17 balls) and Buttler combined to add 60 from the final four overs, with Buttler ending just six runs short of an 11th ODI century.

Bavuma sets up superb chase

South Africa received a boost before their innings began, with wicketkeeper Quinton de Kock cleared to open the batting having missed the last 35 overs of England's effort after suffering a thumb injury behind the stumps.

However, it was Bavuma who got his side off to a flying start. The Proteas skipper took the bulk of the early strike against Woakes and Reece Topley - who had replaced Archer and David Willey - and reached 36 runs, while De Kock, who appeared to be hampered by his injury, was only on four.

However, De Kock eventually cut loose hitting three successive boundaries, the first of which was a six, to spark his innings into life and push South Africa to 54-0 after just seven overs.

England managed to slow the run-rate and were rewarded when Stone struck in his first over, having De Kock well caught in the deep by Duckett for 31.

Bavuma was joined at the crease by the in-form Van der Dussen, who initially continued the form that had seen him score a century on Friday to help his captain keep the scoreboard ticking over.

They played sensibly to rotate the strike and punish the bad balls, and soon Bavuma was nearing a century.

There was extra tension as he needed lengthy treatment after beginning to suffer with apparent cramping in the nineties, but he withstood the pressure and pain to reach 100 by smacking Adil Rashid through extra cover for four.

South Africa were on track as they reached the halfway stage at 164-1, but Bavuma played onto his own stumps to give England a much-needed breakthrough, and when Van der Dussen was caught off Rashid's bowling an over later, the tourists were right back in the game.

However, the new duo of Aiden Markram and Heinrich Klaasen immediately attacked, and put on a quickfire half-century stand for the fourth wicket to keep South Africa on track.

Stone (2-48) was the pick of England's bowlers, and was rewarded with a second wicket as Buttler took a brilliant diving catch to remove Klaasen.

The match was plunged further into the balance when Rashid removed Markram to leave South Africa 284-5 at the end of the 42nd over, with 59 runs need from the final 48 balls.

Some big hitting from Miller looked to have put the game beyond doubt as the South Africa were left needing just 24 from the last 30 deliveries, but tight bowling from Stone and Curran gave England some hope.

The South African pair remained calm, and a Jansen four off the final ball of the penultimate over left them needing just two to win, setting the stage for Miller to smash the disappointing Woakes (0-60) for six down the ground.

What they said

South Africa captain Temba Bavuma:

"A series win is very special. Your disciplines are always tested against England and chasing 340-odd gives us a lot of confidence. It was good I reminded myself how to count to a hundred!

"It could have taken something miraculous for us to lose that game but I think the guys were fairly calm."

England captain Jos Buttler:

"South Africa bowled really well. To come back from early wickets and post the score we did was pleasing but it was a great chase. Bavuma led from the front and the middle order had great momentum. We couldn't pick up wickets early enough."

Former England captain Michael Atherton:

"It shows you how ridiculous a situation it is that South Africa are scrambling to qualify for the World Cup. A side of that ability should be qualifying in the top eight.

"It is a measure of how poorly they have played in the last few years and you felt Bavuma had a point to prove. He picked Rashid and it was a good series win for him as captain against a good England team."

Watch the third and final match of England's ODI tour of South Africa on Wednesday from 10:30am, live on Sky Sports and stream on NOW TV.