The Brazilian held top spot after the delayed first round on Friday and he continued his momentum through the second round, finishing at 14-under.
Before darkness stopped play on Thursday Jaco Van Zyl led the field but the South African had to settle for second behind Da Silva at 11-under in completion of the second round.
"I got a good break yesterday," said Da Silva, who is seeking his first career European Tour win. "It was extremely hard out there for the morning field, and then I got the break and I just started making some putts.
"My putting has been letting me down lately, and it just came alive."
Van Zyl's 67 sees him sit a shot ahead of John Parry (66), who at 10-under has sole possession of third.
Darren Fichardt and Oliver Bekker both hit 67s to take a share of fourth place at minus-8.