Ffion Wynne
BBC Sport Journalist
First ODI, Kimberley
England 186 (38.4 overs): Dean 47* (57); Dercksen 3-16
South Africa 189-4 (38.2 overs): Wolvaardt 59* (114), De Klerk 48* (28)
South Africa won by six wickets; lead series 1-0
England were beaten by six wickets after a below-par showing in the first one-day international against South Africa.
Chasing 187 in scorching conditions in Kimberley, Proteas captain Laura Wolvaardt anchored the innings with a gritty unbeaten 59 from 114 balls to reach the target with 11.4 overs to spare.
England's bowlers toiled, but were left to rue dropping Wolvaardt on five and 27 as the opener held the innings together before Nadine de Klerk's lively 48 not out from 28 balls secured the victory in style.
While the surface was tricky and offered plenty of uneven bounce, England's batters were wasteful in being dismissed for 186 in 38.4 overs.
Number eight Charlie Dean rescued the innings with 47 not out after England collapsed to 106-7, adding 67 for the eighth wicket with Sophie Ecclestone.
South Africa were boosted by the return of all-rounder Marizanne Kapp, who was rested for the preceding T20 series and delivered a new-ball masterclass to take England's first three wickets.
Sophia Dunkley was a late inclusion at the top of the order after Maia Bouchier injured her neck in the warm-up, and was caught behind for four before Tammy Beaumont was bowled for 11 and Nat Sciver-Brunt was lbw for a duck.
Heather Knight's 40 led a brief revival before it was left to Dean and Ecclestone to show some resistance, with Dean matching her career-best score after her partner was brilliantly caught by De Klerk for 17.
South Africa's batters also struggled to score fluently, but they withstood the threat of spinner Ecclestone by playing cautiously through her miserly spell of 0-29, and Wolvaardt's willingness to grind out the runs proved the difference.
The second of three ODIs takes place in Durban on Sunday.
Frenetic England struggle to adapt
Having been so dominant in the T20 series against a depleted South Africa, England were always going to face a a tougher assignment in the ODIs considering the returns of Kapp and seamer Ayabonga Khaka.
Kapp showed her side exactly what they had missed with a relentless opening burst, swinging the ball prodigiously and rarely erring from a testing line and length that England's top order could not withstand.
Dunkley wafted needlessly outside off stump, Beaumont walked down the pitch and played all around a straight one and Sciver-Brunt was trapped plumb lbw to her third delivery.
After Danni Wyatt-Hodge was also pinned in front for 11 by De Klerk and Amy Jones was caught on the boundary for 21, Knight showed how to approach the slow surface, playing late and waiting for the loose ball.
However, a shrewd review from South Africa led to England's captain being given out after a missed sweep, when there had barely been an appeal on the field.
With England on 91-6, Wolvaardt appeared to miss a trick by overlooking Kapp, who still had six overs to go, and kept bowling her spinners because of the variable bounce.
But Dean and Ecclestone looked at ease, happy to rotate the strike for the most sensible passage of play that England managed.
South Africa were guilty of letting the game drift at times, but recovered to wrap up the tail promptly, with Dean left stranded short of her fifty.
Unthreatening England thwarted by Wolvaardt
Wolvaardt had a difficult T20 series but is the world's leading run-scorer in women's ODIs this year, and while this pitch did not allow her to play as fluently as usual, she gave a lesson to England's batters in application.
Her 92-ball fifty is her slowest in ODIs but she was rarely under pressure thanks to the support of her batting partners, with Annerie Dercksen adding 27 to her 3-16 with the ball, Kapp scoring a run-a-ball 22 and De Klerk's attacking innings that included 11 fours.
The concern for England, though, is their lack of creativity in this format. They squeezed Wolvaardt by bowling straight and cut off her favoured shots through the off side but she was equal to it, happy to block when necessary.
When that did not work, they were out of options and, despite the pitch offering plenty of bounce for seamers Lauren Bell and Lauren Filer early, they were too inaccurate and could not benefit from its assistance like Kapp.
The fielding remains a concern, too. Jones strangely went one-handed for the edge behind off Wolvaardt, and Dunkley put down a straightforward chance on the square leg boundary after the Proteas captain miscued a rare Ecclestone full toss.
England are still finding their way back into ODIs after a feast of short-format cricket but, with the Ashes looming against world champions Australia, they need these to figure out a more successful formula in the remaining two matches here.
'Kapp makes such a difference' - reaction
Player of the Match, South Africa all-rounder Marizanne Kapp: "The other bowlers who came on played their part too. It’s a positive win for us to take into the rest of the series."
England captain Heather Knight: "Obviously disappointed but we had some positives. The partnership between Charlie [Dean] and Sophie [Ecclestone] got us into the game but unfortunately it wasn't enough.
"We felt if we took a couple of wickets and we would be in with a chance. But Nadine [de Klerk] put in a brilliant innings and finished it off quickly."
South Africa captain Laura Wolvaardt: "Marizanne Kapp makes such a difference to our side so it's great to have her back and glad to get the win.
"I was pleased with my 50. It was not my ideal innings but it is my role to stay there until the end so I’m glad I could do that."