It was hardly a convincing performance in the scrappy encounter but the Suns showed the hunger and hardness at the ball that was sorely lacking in upset losses to the Western Bulldogs and the Brisbane Lions.
Dion Prestia led the way for the Suns with 31 possessions while stand-in skipper Tom Lynch kicked four goals in what was a niggling affair in front of a crowd of just 12,027.
On a night to forget for Saints fans, Nick Riewoldt was well contained by Steven May in his record 178th game as captain for the club.
St Kilda had lacked the fierce intensity shown in their stunning upset of Fremantle and, too often, shot themselves in the foot with countless mistakes in their defensive 50.
Ahead by just seven at the main break, the Suns set up the 53-point win with a six-goal third quarter before the floodgates opened in the final term.
There was redemption for many youngsters who endured forgettable displays against the Lions, especially Jaeger O'Meara and Harley Bennell.
In a good weekend for the Suns, with a host of results going their way, they sit on 10 wins - equal with sixth-placed North Melbourne and Essendon.
There was a total of 35 clangers from both sides in the mistake-riddled opening term that also featured two heated scuffles.
David Swallow was among the Suns' players lashing out over the boundary line coming up to quarter-time before he was led down the race to have his achilles treated.
Swallow played on impressively with his left calf heavily strapped before being subbed out in the final term.
McKenna had taken a back-to-basics approach in his preparations and was proud his under-pressure players delivered.
"The main thing was the contested footy," he said.
"We've seen them play with that intensity before but not in the last couple of weeks.
"They rolled up their sleeves and got their hands dirty and that was the result tonight.
"Regardless of whether Gary plays or doesn't play, if you get an effort over the footy like that you win most of those games of football."
"It's very hard to defend when you give it back that close to the goal," he said.
"We were really poor with the ball.
"That was the story of the night, we just couldn't look after the footy.
"We just gave the ball back to them way too often.
"We were bold against Fremantle ... we tried to go."