South Africa captain AB de Villiers won the toss and elected to bat against Pakistan in a day/night Champions Trophy match at Edgbaston on Wednesday.
The Proteas were unchanged from the side that beat Sri Lanka by 96 runs in their Group B opener at the Oval on Saturday.
South Africa stand at 213/8 after 49 overs with Morne Morkel and David Miller at the crease. Hashim Amla and De Koc succumbed to lbw appeals to Imad Wasim and Muhammad Hafeez deliveries. De Villiers and Wayne Parnell returned to the pavilion without any runs.
Pakistan, however, made two changes following their humiliating 124-run defeat by arch-rivals and title-holders India at Edgbaston on Sunday in a match they had to win to stand a chance of reaching the semi-finals of a tournament featuring the world's top eight one-day international nations.
They gave an ODI debut to Fakhar Zaman, a 27-year-old left-handed batsman who has played three Twenty20 internationals.
Fakhar's inclusion, in place of the dropped Ahmed Shehzad, added variety to an otherwise all right-handed Pakistan top order.
Meanwhile paceman Junaid Khan replaced Wahab Riaz, who suffered a tournament-ending ankle injury against India while falling in his delivery stride after being smashed for 87 runs in just 8.4 wicketless overs.
Junaid took four for 73 in a warm-up match against Bangladesh.
South Africa's side featured Pakistan-born leg-spinner Imran Tahir, who took four for 27 against Sri Lanka. Meanwhile, Pakistan were coached by South African Mickey Arthur.
Pakistan: Azhar Ali, Fakhar Zaman, Babar Azam, Mohammad Hafeez, Shoaib Malik, Sarfraz Ahmed (capt/wkt), Imad Wasim, Mohammad Amir, Shadab Khan, Hasan Ali, Junaid Khan,
South Africa: Quinton de Kock (wkt), Hashim Amla, Faf du Plessis, AB de Villiers (capt), David Miller, JP Duminy, Chris Morris, Wayne Parnell, Kagiso Rabada, Morne Morkel, Imran Tahir,