Ab de Villiers and Hashim Amla stole the show as South Africa hammered England by nine wickets to clinch a 2-0 Twenty20 series victory.
De Villiers (71) was at his swashbuckling best and recorded his fastest T20 half-century with six sixes and as many fours, while Amla was unbeaten on 69 in the Proteas' score of 172-1 - England's Chris Jordan (0-48) particularly toiling against the duo.
Earlier, Jos Buttler (54) and captain Eoin Morgan's 96-run stand helped England recover from 66-3, but the tourists were 171 all out in Johannesburg after a devastating collapse.
The Proteas have now beaten England in ODI and T20 series and are in good form ahead of the World Twenty20, but Morgan has plenty to ponder before heading to India.
After an off-colour Jason Roy (9) went early, Joe Root (34) and Alex Hales (16) shared a 50-run stand, but fell in the space of two balls, the latter run out after miscommunication with -Morgan.
Buttler smashed consecutive sixes off Duminy in the 15th over as he and Morgan rebuilt the tourists' innings.
But the wickets arrived in twos again. Buttler was caught by a stooping Faf du Plessis in the covers and then Morgan was run out as Kyle Abbott (3-26) got a fingertip to Ben Stokes' first-up drive, which clattered into the stumps at the non-striker's end.
After England's final five wickets fell for a paltry 13 runs, it was the De Villiers and Amla show.
De Villiers launched into Jordan's first over, England's third, scoring 22 to tilt the balance irreversibly in the Proteas' favour, including a violent blow from an attempted short ball over the seep square leg boundary.
Jordan and Stokes had no answer to the opening pair and the hosts were 84-0 from the powerplay.
The introduction of Adil Rashid (1-30) fared little better for Morgan, the spinner dragging down his first delivery and getting duly deposited in the stands by De Villiers, who racked up his 21-ball fifty in the same over.
Rashid would get a modicum of revenge as De Villiers picked out Root on the long off boundary attempting another lusty blow, but the damage was done.
It did nothing to derail South Africa. Amla reached 50 off his 27th delivery and, together with captain Du Plessis (22 not out), steered South Africa home with 32 balls remaining.