Matthew Breetzke scored an unbeaten 59 as South Africa A were bowled out for 131 on day two of their four-day match against Sri Lanka A in Pallekele.
Breetzke struck five fours during his 93-ball knock.
Keegan Petersen (19) and Dewald Brevis (16) were the only other batsmen to reach three figures.
Spinner Lakshitha Manasinghe starred with the ball for the hosts, picking up 5-19.
Sri Lanka A made 325 in their first innings, with SA A spinner Senuran Muthusamy taking 7-123.