Saturday's 3-1 win over Birmingham hauled the Black Cats ten points clear of the relegation zone, a healthy cushion with eight games of the season to play.
One more win should be sufficient to secure Premier League safety, and after a spell of playing with the threat of relegation, Campbell is looking forward to travelling to Aston Villa tomorrow with some of the tension lifted.
When you are right on the fringes of relegation, it's not nice, said the striker, who has scored two goals in his last three matches. You can't relax, but we've earned ourselves some breathing space.
We can now try to concentrate on playing good football because we have that extra daylight. You can never chill out in this league, but it's nice to know we have ten points over the bottom three.
Anything can still happen, and we could still go on a bad run or a great one. But with the wins and points we have picked up, we are in a different frame of mind.
Campbell has helped Sunderland claim seven points from their last nine matches, but the club's most important player has undoubtedly been goalkeeper Craig Gordon.
The Scotland international made a string of saves against Manchester City, and was at it again last weekend as Birmingham's second-half comeback was thwarted.
Craig is a great goalkeeper who plays at international level and is highly regarded in those surroundings, said Campbell. He has had a few injury problems but is back playing regular football now. He's back to his best and long may it continue.
He is very good. There are some quality keepers in the Premier League but, in the last two games, I wouldn't say there is anyone out there better than him.
At this stage, he is that good, and I'm confident he can continue like that. He has saved us in the last couple of matches.
While Campbell is looking to help Sunderland climb further up the table in the final six weeks of the season, his club mate Daryl Murphy is hoping to engineer a permanent move away from the Stadium of Light.
Murphy has scored six goals in 11 matches since joining Ipswich on loan in January, and is hoping Sunderland do not price him out of a full-time move to Portman Road in the summer.
I don't know what price is going to be put on my head, said the Republic of Ireland international. I hope the price is not too restrictive, because I just want to play football.
I've got my chance here, and I'm enjoying my time working with Roy Keane again, as I did at Sunderland.
Long may that continue.
Supporters can buy tickets for tomorrow's game from the ticket office at Villa Park's Doug Ellis Stand on the evening of the game. Tickets are priced at £36 adults, £26 over-65s and 17-20s, and £22 Under-16s.