Goals from James McArthur and Chris McCann sealed the Latics third win on the row after earlier victories against Barnsley and Cardiff.
Speaking to the Wigan Evening Post, Al Habsi said: "The team is playing fantastic football, especially away from home.
"It's been a tough week for us, but you can't do any better than three wins in seven days. It was a very difficult game, because Brighton are a very good side and deserve to be where they are near the top of the league.
"But we looked very strong, very solid, very professional. The last fifteen minutes was always going to be tense against a team pushing for goals.
"But we defended very well and deserved to win the game."
The win lifted the Latics to within a point of the play off places with a game in hand over sixth placed Reading.