The Seagulls won 2-1, with Danny Welbeck scoring in the second-half of extra-time.
Hurzeler said: “We have to understand it is always about togetherness.
"You need special players like Solly (March) with the assist, Danny with the finish to win games like this here.
“But we also have to see how hard the other players worked for this win.
“They always stayed together and that was the key for today.”
The German also stated: “Not only the character but also I think the performance was quite impressive.
“Of course we had some setbacks during the game but we reacted always in a good way.
“We stayed very calm.
“We found the good balance between defensive stability and controlling the game in possession.
“Then we had of course some phases of the game where we had to suffer.
“In the end, we did it in quite an impressive way."