Sunderland chief Martin O'Neill believes their lack of midweek action played a key role in their FA Cup success over Arsenal.
The Black Cats booked their place in the quarter-finals of the FA Cup with an impressive 2-0 win over Arsenal at the Stadium of Light to compound a miserable week for the Gunners following their Champions League humiliation in midweek by AC Milan.
O'Neill was happy to turn the tables on Arsenal after they came from behind to win late on last weekend in the Premier League with the Sunderland boss feeling his side's energy was an important factor in the victory.
"I think that helped us immensely," said O'Neill of the midweek rest. "We had lots of energy, if anything we were getting stronger as the game was going on.
"The last 15 minutes of last week I thought we were really tired but I think the advantage swung our way this week."
O'Neill was delighted to reach the last eight and admits there is a growing self-belief within the squad of success.
He added: "I'm really, really delighted for everybody concerned with the football club and the players in particular.
"I thought they were excellent today, not just working hard but when we had the ball.
"There's plenty of self-belief about the team, that's getting stronger and I think they feel as if they can win matches, which is great."