Worcestershire 2016 overseas player Kyle Abbott made important contributions with the ball and then the bat as South Africa edged out England by one wicket in the fourth ODI in Johannesburg.
Abbott picked up two wickets as England were bowled out for 262 after being put into bat.
He then came to the wicket with South Africa 210-8 and, although he only made three not out, it was crucial that he stayed with big-hitting Chris Morris who hit 62 off 38 balls.
Morris was dismissed with the scores level after he and Abbott had added 52 but Imran Tahir saw South Africa home with a boundary off Adil Rashid.
It levelled the series at 2-2 ahead of Sunday's decider in Cape Town.
Abbott had sent back Jos Buttler and his soon to be County colleague Moeen Ali in successive overs as England nose-dived from 87-1 to 108-6 after being put into bat.
Abbott, who will link up at New Road in early July for the rest of the season, played a part in the first dismissal of the day in Jason Roy (6).
The Surrey player went to hook Kagison Rabada and top edged a catch to Abbott running in from fine leg.
Abbott took the new ball and bowled four overs for 21 runs in his first spell. But he enjoyed his double success when returning for another two over burst.
First Buttler (1) top edged an attempted pull and the ball ricocheted off his helmet and ballooned up to Abbott who held onto the catch.
Then Moeen (4) tried to force the ball through the covers and edged through to Hashim Amla who took a head high catch at slip.
But Root scored a superb 109 and shared in a seventh wicket stand of 95 with Chris Woakes (33) before a late order 39 from Rashid boosted the final total to 262 all out in 47.5 overs.
Abbott finished with 2-57 from nine overs and Rabada 4-45 from 9.5 overs.
South Africa lost wickets at regular intervals with numbers two to seven all getting starts and scoring between 21 and 38.
Moeen bowled nine tidy overs for 39 runs and conceded one boundary.
It looked all over as South Africa were reduced to 210-8. But then came the final twist in the tail with Abbott playing his part in blocking one end while Morris cut loose.