Last night, viewers saw EastEnders secure the gong at the O2 arena in London, triumphing over Corrie, Emmerdale and Hollyoaks.
Speaking on ITV2's National Television Awards Party after the ceremony, Wallace explained that the victory came as a surprise following Corrie's recent 50th anniversary celebrations.
The actress - who plays Walford's Kat Moon - explained: "I thought that Corrie would be in with a good chance because it was their 50th anniversary, they had a great live episode, the tram crash - brilliant, fantastic. I really thought they'd win it. It goes to show that EastEnders just gets stronger and stronger every year."
Asked whether there is a rivalry between the soaps, Wallace replied: "I never feel like that. I support all of them. And also because I was part of the 50th anniversary of Coronation Street because I did The Road To Corrie. So it's great to be a part of that. I don't see it as a rivalry."
Wallace was also asked whether she had found it difficult to film the soap's cot death and baby swap storyline, which has seen Kat left grief-stricken following the apparent loss of her newborn son Tommy.
She replied: "Yeah, it's hard because it's a sad story, but as an actor you do it and you can walk away from it - that's the thing."
EastEnders won three awards in total last night as Ricky Norwood (Fatboy Chubb) was named 'Most Popular Newcomer' and Lacey Turner (Stacey Branning) took home the 'Serial Drama Performance' gong.