Left-arm spinner Tabraiz Shamsi grabbed four wickets as South Africa bowled out Pakistan for 270 in their World Cup match in Chennai on Friday.
The 33-year-old finished with figures of 4-60 while paceman Marco Jansen took 3-43 after Pakistan won the toss and batted, looking for a win to revive their World Cup hopes.
Pakistan have lost three of their five matches while South Africa have four wins and one loss.
Middle-order batter Saud Shakeel scored a fighting run-a-ball 52 and skipper Babar Azam a solid 65-ball 50 while Shadab Khan chipped in with an aggressive 36-ball 43.
Pakistan can take heart from the fact that South Africa collapsed to an upset defeat against the Netherlands while chasing 246 in Dharamsala last week.
Pakistan would have scored fewer runs had Shakeel and Shadab not lifted them with an 84-run stand for the sixth wicket off 71 balls following Azam's dismissal at 141.
Shadab hit two sixes and three boundaries while Shakeel's second fifty in the tournament had seven hits to the rope.
It was Jansen who hit Pakistan early with the wickets of openers Abdullah Shafique (nine) and Imam-ul-Haq (12) in the first seven overs.
Azam added 48 runs for the third wicket with Mohammad Rizwan who made 31 with a six and four boundaries.
The skipper added another 43 for the next wicket with Iftikhar Ahmed who scored 21 with a six and a boundary.
Shamsi dismissed Iftikhar caught at long-on and Azam behind the wicket sweeping to derail the innings until Shakeel and Shadab rebuilt.
Fast bowler Gerald Cotzee broke the stand by dismissing Shadab in the 40th over while Shamsi sent back Shakeel and Shaheen Shah Afridi (two).
Brief Scores: Pakistan 270 all out in 46.4 overs (Saud Shakeel 52, Babar Azam 50; Tabraiz Shamsi 4-60)