Fast bowler Shamar Joseph took five wickets as West Indies bowled South Africa out for 160 on the opening day of the second and final Test on Thursday, but the home side are struggling on 97 for seven in reply on a lively pitch in Guyana.
Seventeen wickets fell in the day as seamers from both sides were able to get movement off the pitch and through the air after South Africa had won the toss and elected to bat.
Jason Holder is not out on 33 and will look to guide his side past the visitors' first innings score on the second morning, but needs to do so before he runs out of partners.
Wiaan Mulder has career-best figures of 4-18 as he ripped through the West Indies top order, bowling captain Kraigg Brathwaite (3) and completing a brilliant one-handed caught and bowled to remove Alick Athanaze (1).
"The ball stayed quite low, so it was about trying to hit the stumps. I did not bowl at my best, but it went for me today," Mulder said. "Shamar bowled really well and made it tough for batters to score and I tried to replicate that."
The home side were in desperate trouble at 56-6, but Holder embarked on an excellent counter-attack and put on 41 for the seventh wicket with left-hander Gudakesh Motie (11).
The latter was out to the final delivery of the day, trapped leg before wicket by spinner Keshav Maharaj as the pitch also began to take turn.
Joseph bagged figures of 5-33 as the West Indies earlier dismissed South Africa inside 54 overs with some superb fast bowling.
The tourists were reduced to 97-9 but a 63-run 10th wicket stand between Dane Piedt (38 not out) and Nandre Burger (23), a record for South Africa against the West Indies, took them to what looks a respectable first innings score in the conditions.
The home bowlers were getting prodigious swing with five of the South African batters clean bowled and seamer Jayden Seales also taking 3-45.
The first Test in Port of Spain was heavily affected by rain and finished in a draw.
