A tough run of fixtures face the Latics starting with the visit of Arsenal on Saturday.
The Gunners were held 1-1 at home by Fulham last week and Di Santo is hoping the Latics can get a result against Arsene Wenger's men.
Speaking to the club's official website, he said: "This win [Sunderland] will give us a big confidence lift going into the Arsenal game, and we have to try and stay at this level in the coming weeks.
"It's important we build on this now and try to get a little run going because December is both a very tough month for us and one that will ultimately have a massive say on where our ambitions for the rest of the season.
"We need the fans to help us against a very strong team, but we know that we have the ability to beat anyone and can create an atmosphere at home that will give us the edge as it has done in the past."
The young striker has given manager Roberto Martinez a real selection headache in the forward positions. Hugo Rodallega is now fully fit, whilst Conor Sammon has been in good form. Aligned with the good performances of Victor Moses, the resurgence of Jordi Gomez, and Albert Crusat's first goal for the club, there is plenty of competition up top.
