The New Zealander finally made his first cut since last October, but did it only after a wait of nearly eight hours and only when England’s Phillip Archer and Swede Ake Nilsson both failed to end their rounds with birdies late in the evening.
Campbell has been struggling with a shoulder problem and pulled out of The Open during his second round last week.
After an opening 78 another early exit was on the cards, but he improved eight strokes on that on his return to Barseback – at 7,665 yards the longest course in European Tour history – and then spent the rest of the day wondering if two over par was good enough to survive.
“I’ve had a mental barrier to get through as well as physical,” he said. “A lot of people around me have been very supportive, but the bottom line is that it’s up to you.
“I’d be a rich man if I was paid something every time somebody has asked me what’s happening, but hopefully I’ve turned the corner now.”
Gonzalez and Slattery, who got away from golf in very different places and in very different ways last week, are 10 under par and nine under respectively.
Gonzalez, who after failing to qualify for The Open returned to Argentina and worked on his farm all week, had his second successive 68, while first-round pacesetter Slattery, who went on picnics in the Lake District, added a 70 to his sparkling opening 67.
“I had to stop thinking about golf for a while,” said the 30-year-old from Southport, who has fallen to 136th place on the European money list and 504th in the world this season.
“Not only did I leave my clubs behind, I didn’t even take my phone.”
For the second day running the former Challenge Tour winner, yet to taste victory on the main circuit, was forced off the Barseback course by an approaching storm.
In the first round it rather took the wind out of his sails after he had raced to an outward 30, but this time it worked in his favour.
He said: “It was getting really windy when we stopped, but it had died down as we went back out.”
Slattery finished with a superb 287-yard three-wood onto the green at the long ninth and two-putted for birdie.
Gonzalez is also having a rough year, finding himself 153rd in the ‘Race To Dubai’ standings and 316th in the world rankings.
His ‘Handicap Cero’ farm south of Buenos Aires is also an education centre for youngsters.
“I started at around 8am each day and worked through until about seven,” said Gonzalez.
Pre-tournament favourite Henrik Stenson, who is donating all his prize money to his new Foundation charity, was relieved not to leave empty-handed after a closing birdie removed the threat of missing the cut.