The Argentinian scored the Latics' second goal after some neat link-up play with new strike partner Arouna Kone.
Taking last season's games into consideration, the 23-year-old has five goals in eight league games. Martinez has lauded the forward's ability, claiming that he can be an "outstanding" player for the club.
"He is a striker with a tremendous touch, great finishing and energy and I think he can be outstanding in every aspect as a centre-forward," said the Wigan boss.
"You look at the second goal and it is as good as you are going to see in terms of centre-forward play.
"He is doing his duties defensively, in the counter-attack there is outstanding link-up play with his partner, and then he is as composed as you can be in the box."
Di Santo joined Wigan in 2010 from Chelsea.