Demba Ba scored twice, the first from a disputed penalty which saw the Latics' Maynor Figueroa sent off, before Gael Bigirimana's first senior goal rounded off a 3-0 victory.
It ended a run of four-straight defeat for the Magpies and Krul said: "It's a massive win for us, we knew we needed the three points.
"The pressure was on but the intensity we had at Stoke, we did that again and started really well. We must be proud, we can take a lot of confidence from this – we needed this.
"I think tonight we showed what a quality team we are. I don't think we've had many breaks this season, we've lost a lot of players and luck has not been on our side.
"It has been hard, so many injuries and losing games is a new experience for us, especially after last season, but we need to stick together."