Goal scorer Heskey remarked: "We battled away. We knew all about coming to Chelsea, it's always a big game and they are chasing Man U.
"But we need the points too and we battled away and got quite a few chances and took the one at the end.
"It's just one point but it keeps us up there."
The draw was important to Wigan's hopes of beating relegation but it would not have been possible without goalkeeper Chris Kirkland, who was in excellent form.
Kirkland said: "I just had a feeling about tonight. The last few weeks have been superb and we've got ourselves into a good position.
"There are still four games to go, and tonight was a bonus."