Wilmington midfielder Mael Corboz got the Hammerheads on the score sheet in the 34th minute with a low, driving goal.
After a run down the right side, midfielder Austin Martz laid the ball off in the center of the box to Corboz, who sent it just past RSL goalkeeper Jeff Attinella.
RSL's attack was anemic up top with Devon Sandoval, but a few first half highlights came at the feet of Burrito Martinez.
The Argentine midfielder nearly chipped Wilmington goalkeeper John Smits in the 13th minute after a nice pass from Chris Wingert. A second chance came in the form of a beautifully lofted pass in the 25th minute from Martinez into the path of Jordan Allen, but he whiffed on the shot.