Leg-spinner Imran Tahir took four wickets while Jean-Paul Duminy and Faf du Plessis scored half-centuries to help South Africa beat Pakistan by 68 runs in the third day-night international in Dubai.
Tahir wrecked Pakistan’s middle order with figures of 4-53, to bowl them out for 191 in 44.3 overs after they were set a challenging 260-run target at Sheikh Zayed Stadium on Wednesday.
The emphatic win gives South Africa a 2-1 lead in the five-match series.
Both teams will meet again at the same venue on Friday before the series is rounded off in Sharjah on Monday.
South Africa won the first match in Sharjah by one run while Pakistan won the second match in Dubai by 66 runs.
Tahir, who conceded 18 in his first two overs, returned for a second spell, triggering a batting collapse which saw Pakistan lose five wickets for 30 runs.
Tahir trapped Misbah-ul Haq (19), caught and bowled Umar Akmal (seven) and Asad Shafiq (11) caught at cover to leave Pakistan struggling at 116-7.
Wahab Riaz, who top-scored with 33, added 61 for the eighth wicket with Sohail Tanvie (31), but it only delayed the inevitable.
Pakistan had raced to 50 by eighth over as Ahmed Shehzad, who hit half-centuries in the first two games, hit three boundaries off Lonwabo Tsotsobe in the fourth over and then added two more off Morne Morkel in the next.
But spearhead Dale Steyn, who missed the first two matches to rest at home, struck in his second over, removing Shehzad caught in the slip with a sharp outgoing delivery.
Two runs later, Mohammad Hafeez played Morkel (2-35) straight into the hands of point after making 15.
Misbah and Umar Amin (13) attacked Tahir with four boundaries in his first two overs, but the leg-spinner had the last laugh, taking three wickets in the space of 31 runs.
It was Jean-Paul Duminy (64) and Faf du Plessis (55) who anchored the South African total after they won the toss and batted.
Duminy hit three boundaries off 89 balls and gave the innings the much needed impetus with a 66-run fifth wicket stand with David Miller (34), adding 65 in the last ten overs.
Du Plessis had steadied the innings during his 60-ball knock, adding 77 for the second wicket with Quinton de Kock who made 40 from 57 balls.
