A disciplined bowling effort from England Under-19s restricted their South African counterparts to 268 for four on the first day of the first Test at Fenner's.
Will Rhodes' men were made to toil for their wickets but managed to keep a lid on the South African scoring rates before an unbeaten 96 from Grant Roelofsen gave the advantage to the Proteas late on.
Ryan Rickleton anchored the innings for the visitors with a patient 76 before wicketkeeper Roelofsen and captain Sibonelo Makhanya piled on the runs as the day drew to a close.
Yorkshire bowler Matt Fisher took the first wicket of the day, removing opener Matthew Christensen for single figures, and Josh Shaw picked up Marcus Ackerman cheaply to reduce South Africa to 36 for two.
Johannes Malan stayed with Rickleton until he was trapped in front by Nottinghamshire's Luke Wood for 31 but that brought Roelofsen to the wicket, who stayed with the not out opener for nearly 40 overs.
A masterstroke from Rhodes paid off when Ed Barnard dismissed Rickleton shortly before the new ball was due, but the South African duo of Roelofsen and Makhanya stood firm to put themselves in a good position ahead of day. two.