The Pakistan Cricket Board has decided to keep Muhammad Rizwan and Abid Ali in England for the duration of the World Cup as back-up players.
The 30-year-old made 115-ball 101 not out in the five-match series opener in Sharjah.
Asif Ali and Faheem Ashraf starred for Islamabad United as they beat Lahore Qalandars by five wickets.
Pakistan made two changes, with Faheem Ashraf and Mohammad Amir returning at the expense of Hasan Ali and Usman Shinwari.
Pakistan bowling coach Azhar Mahmood said the remaining Pakistan batsmen would need to follow the example of De Kock and Hashim Amla.
Set to make a daunting 381 to win, Pakistan were 153 for three at the close, needing another 228 runs.
De Kock equalled his Test-best score of 129 before South Africa were bowled out for 303.
De Kock batted fluently in reaching his fifty off 49 balls.
From being in control on 226 for three at tea, South Africa were bowled out for 262.
Pakistan's bowlers changed the course of the third and final Test against South Africa when they engineered a dramatic collapse on the first day of the third and final Test on Friday.