Senuran Muthusamy starred for South Africa A on day one of the first four-day match against Sri Lanka A in Pallekele.
The left-arm spinner took 7-123 as the hosts were bowled out for 325 in 83 overs on Monday.
Seventeen-year-old pace bowler Kwena Maphaka picked up two wickets on his first-class debut, and Tristan Stubbs one with his part-time off-spin.
Opener Lasith Croospulle top-scored for Sri Lanka A with 98, before being trapped lbw by Muthusamy. He and Lahiru Udara (42) put on 66 for the first wicket.
No 8 batsman Ramesh Mendis scored 78 as the hosts’ tail wagged.
