The in-form striker got the only goal - his fifth of the season - early in the second half as Martin O'Neill's side added a first win to their four league draws so far in an unbeaten start to the campaign.
"We're delighted to get the three points and it's been coming, I think," he told SAFC TV afterwards.
"We were disappointed to concede the goal last week but it was great to get the win today.
"Wigan are a strong, physical side but we held our own. It was a bit easier when they went down to 10 men and I think we deserved the win today."