Sunderland goalkeeper Simon Mignolet believes confidence in the Black Cats camp has flourished since Martin O'Neill took over as manager.
The 23-year-old pulled off an impressive double save late on against Everton on Saturday to keep Sunderland's FA Cup hopes alive, with the quarter-final tie ending in a 1-1 draw to set up a replay.
The Wearsiders are also on course for a top-10 Premier League finish having enjoyed a run of good results since O'Neill succeeded Steve Bruce at the helm in December last year.
Belgium international Mignolet feels the Black Cats are a different side since the manager's arrival.
"There's been a big difference here since Martin O'Neill took over," he said in the Daily Mirror.
"A lot of good wins have helped the confidence too, but that can change really quickly.
"The main thing is to follow up because the games are coming quickly."
Sunderland were pegged back in the first half against the Toffees after Tim Cahill cancelled out Phil Bardsley's opener.
Mignolet believes David Moyes' side will prove just as tough opposition in the replay, adding: "Everton always fight really hard. For 20 minutes we were the better team, but they came back at us. So the replay won't be easy either."
The keeper's crucial save came in the dying minutes when he clawed out John Heitinga's header before turning away a follow-up from Nikica Jelavic.
"Heitinga's header was going just inside the post, but luckily I got a hand on it," he said.
"Unfortunately it dropped for Jelavic and all I could think of was getting up as quickly as I could - and lucky for me, he hit it into the side of my body.
"I didn't know too much about it, but as a goalkeeper you try to make yourself as big as you can and luckily for me I blocked it so I made myself big enough!"