Rangel, who worked under now Wigan boss Roberto Martinez when he was at Swansea, volleyed home the visitors' first and said that three points were crucial for them this evening.
"We've had a run of bad results, seven games without a win and today was important to get three points," he told Sky Sports News.
However, the Spaniard is hoping that the result doesn't condemn Wigan to relegation.
The Latics' future is now out of their hands as they are three points adrift of safety with just two games to play.
"[The result tonight] makes it difficult for them to stay up but there's still two games left and hopefully they will stay up," added Rangel.
"Obviously I think about our team and it's a great three points for us."
Victory for Swansea sees them move within two points of eighth-placed West Bromwich Albion.