Batsman Loots Bosman, veterans Neil McKenzie and Roger Telemachus and spinner Thandi Tshabalala are all in the Twenty20 squad for the match in Johannesburg.
Wickets were soon falling too, Loots Bosman mis-pulling Stuart Broad to mid-wicket and Herschelle Gibbs beaten by some smart recovery work in the covers from Collingwood to be run out for one as he tried to return for a second.
Roach's hat-trick, with the first three balls of the 32nd over (his ninth), saw Pieter Sielaar and Bernard Loots beaten for pace and trapped lbw, before last man Berend Westdijk had his middle stump flattened in emphatic style.