Kent's Joe Denly completed a double century before the England Performance Programme squad declared their first innings at 425-9 before lunch on the second day against Nashua Titans in Pretoria.
Resuming on 188, Denly advanced to 217 - his career-best score although the match does not carry first-class status - while Ajmal Shahzad hit a swift 33 in a stand of 71 for the eighth wicket.
Shahzad also starred with the ball, taking 4-37 as he and Sajid Mahmood (3-51) helped roll over the hosts for 235 in reply.
Lancashire's Francois du Plessis enjoyed himself for Titans, hitting 124 not out.
The EPP moved to 44-1 by stumps to take a lead of 234 into day three.