Olly Stone was the star as England Under-19s assumed a strong first-innings lead of 119 over South Africa.
The Northamptonshire seamer, who is also captain of the side, bagged 4-40 from 11 overs as the hosts were dismissed for 194 at Newlands.
Jonathan Tattersall and Dominic Sibley then played out nine overs without alarm to close day two of four on 24 without loss for a lead of 143.
Ed Barnard earlier added seven to his overnight 107 as the tourists improved on yesterday’s 277 for seven by 36.
Stone introduced himself to the attack in the 39th over and soon struck twice in two balls, bowling Murray Coetzee for 50 through the gate and having Vassilli Orros held at second slip.
David Bedingham offered some resistance only to top-edge Stone to mid-on. Three wickets fell in as many overs with Clyde Fortuin mis-timing Josh Shaw to midwicket and Michael Fassen edging Stone behind.
That left the hosts 165 for eight and, when Lizaad Williams skied a slog-sweep to slip, Hammond had the last wicket given Craig Kirsten was yesterday ruled out of the game with a stress fracture of the lower back.
Stone - who only chose to bowl as the fifth-change option - had earlier scored 29 with the bat in England’s 313 all out.