Erwee (85) and Hamza (78) shared an unfinished 153 run partnership for the second wicket after the fall of skipper Pieter Malan as the hosts led by 188 runs with one more day to go in the four-day Test.
Resuming at 229 for six, India A folded for 276 in 90.1 overs for a first-innings lead of just eight runs.
For the hosts, fast bowler Lutho Sipamla (5/99) completed a five-wicket haul.
#SAAvINDA Day 3 | STUMPS🇿🇦 An unbeaten 153-run second-wicket partnership between Sarel Erwee (85*) and Zubayr Ham… https://t.co/BPNrVBFtDu
— Cricket South Africa (@OfficialCSA) 1638978483000
Overnight batsman Ishan Kishan could add just five more runs to his score before he was dismissed by Marco Jansen. Navdeep Saini provided some resistance with a 22-ball 27 before Sipamla mopped up the tail.
Indian bowlers then found the going tough with Saini being the only one to get a wicket when he dismissed Malan for the second time, trapping him in the 15th over.
Erwee and Hamza then kept things under control and were at the crease at the draw of stumps.
South Africa A: 268 & 196 for 1 in 58 overs (S Erwee 85, Z Hamza 78; N Saini 1/49).
India A: 276 all out in 90.1 overs (I Kishan 91, H Vihari 63; Sipamla 5/99).