Cattermole has underlined the importance of the Black Cats' quarter-final victory over the Blues by emphasising the effect it will have as they seek league safety.
Sunderland appeared to be heading out at the Stadium of Light on Tuesday night when they trailed with two minutes to go after Cattermole's own goal shortly after half-time.
However, Fabio Borini struck to send the match into extra-time and more was to come with Ki Sung-yeung scoring the winner in the final minute to send the Cats into the last four.
Cattermole though reiterated that staying in the top flight is the priority with the Premier League's bottom side hosting fellow strugglers Norwich on Saturday.
Cattermole told Sky Sports: "There's been some positive performances throughout.
"It's a great win, it's not the league but it gives some momentum going into Saturday.
"The priority was always Saturday but we got the win and it gives us some belief, it's massive for the squad's confidence."
Ki was ecstatic after scoring and said: "It was just unbelievable.
"I didn't expect to score but I am really pleased to help the team go through.
"This was a very hard game for us, we didn't give up... the boys played unbelievable."