London: A dramatic batting collapse cost England against South Africa as they lost the final one-day international by seven wickets at Lord's on Monday.
The hosts were reduced to 20-6 after five overs as Kagiso Rabada and Wayne Parnell struck in overcast conditions.
South Africa briefly wobbled after losing Hashim Amla (55) but chased down the total with relative ease.
Earlier, Rabada sparked a dramatic England collapse as England slumped to 20 for six in five overs after losing the toss before recovering to 153 all out.
Fast bowler Rabada took four wickets for 12 runs in his first three overs, before eventually finishing with four for 39 in nine.
New ball colleague Wayne Parnell took three for 43 in eight.
Jonny Bairstow, recalled for this match, kept the Proteas at bay with a fine 51.
His was one of just three double-figure scores by batsmen in the innings, with David Willey (26) and number nine Toby Roland-Jones, who made an impressive 37 not out on his ODI debut, helping the Yorkshireman compile stands of 62 and 52 respectively.
Nevertheless, there were still nearly 20 overs of the innings left when Keshav Maharaj dismissed last man Steven Finn.
Left-arm spinner Maharaj took three for 25 in 6.1 overs.
Bairstow, England's Test wicket-keeper who many believe should be in England's first-choice ODI side purely as a batsman, stopped the rot.
He showed his class by cover-driving Rabada and cutting fast bowler Morne Morkel for fours.
Bairstow received good support from Yorkshire team-mate Willey before the all-rounder was caught drove Parnell to cover.
Bairstow then gave his wicket away when he charged at Maharaj only to be stumped by de Kock to end a 67-ball knock featuring eight fours.
Roland-Jones struck five fours but the damage had long since been done.
England, who sealed the three-match series in Southampton on Saturday, put in a valiant performance with the ball - but their batsmen lacked concentration in their final match before the Champions Trophy.
The hosts - who play Bangladesh at The Oval in the first match of the tournament on Thursday - remain the favourites to secure their first 50-over title.
Brief scores
England - 153 (Bairstow 51, Rabada 4-39, Maharaj 3-25, Parnell 3-43)
South Africa - 156 for 3 (Amla 55, Ball 2-43)
Result - South Africa won by 7 wickets