We dominated from kick-off but it took until the 29th minute to break through a determined Wigan defence when Luka Modric played in Gareth Bale, who controlled and volleyed home.
Luka quickly made it 2-0 with a sweet strike from 20 yards but although we were in complete control, we lost Rafa to a calf problem and Harry felt that affected our forward play for the rest of the match.
In-form Gareth drilled home the third on 64 minutes before James McArthur pulled a deserved consolation back for the visitors.
The win stretched our run to just two defeats in 21 matches in the Premier League and it was a good night for us with both City and Chelsea dropping points.
"We played ever so well in the first half, went 2-0 up but then we had a problem," said Harry. "We lost Rafa to injury and then we had Ade up front on his own and no more strikers.
"That meant the only support for Ade was Niko and Gareth, who were excellent.
"We were completely in control in the first half and played some great stuff.
"It was harder in the second half. We didn't have a forward ball, so we had possession and took longer to get forward. We didn't play with the same fluency as we did in the first half, but it was still a great performance."
Young development squad striker Cameron Lancaster was named on the bench and got his chance in the final 10 minutes.
"I thought he did ever so well," said Harry. "It was great for him to come on and make his debut."