The striker's scrambled 46th-minute touch hoisted the Perth Saints level on points with the 10-man Buddies.
Kane's goal proved vital for a side who had not won since early November.
Both managers opted to make two changes from their previous starting line-ups, with captain Jason Kerr and Craig Bryson replacing benched duo Liam Craig and Murray Davidson for the Perth Saints, while Cameron MacPherson and loan recruit Eamonn Brophy came in for Kyle McAllister and Ethan Erhahon for the Buddies.
In the ninth minute, tenacious play from Bryson prevented the ball from rolling out for a goal-kick and, when Kane teed up a cross for Scott Tanser, Guy Melamed was unable to get a decisive touch to worry the visitors.
In their next attack, Shaun Rooney's low cross found no takers in the six-yard box.
Northern Ireland international Ali McCann required treatment to a head wound and, while he was off getting treatment, David Wotherspoon swept a 25-yard free-kick inches wide of the target in the 21st minute.
Joe Shaughnessy rose to head a free-kick past Zander Clark's left hand upright and, at the other end of the pitch, the St Mirren captain had to be alert to produce a well-timed block tackle which prevented Melamed from firing the Irishman's former club in front after 29 minutes.
Seconds before the break, MacPherson was cautioned for a needless foul on Melamed.
It was to prove costly, as the Buddies midfielder caught Melamed again in the 55th minute and, despite his protests, referee Steven McLean produced a red card.
By that stage, the Perth Saints had seized the lead in the 46th minute, when Kane stabbed home the rebound from close range after keeper Jak Alnwick failed to hold his powerful initial effort.
Kane could have doubled the lead in the 67th minute, but he fired his shot over the crossbar from 12 yards after being picked out by Wotherspoon.
Shaughnessy rose to head a Jamie McGrath free-kick over the bar in the closing stages as the short-handed Buddies sought an equaliser.
St Johnstone substitute Murray Davidson was booked in the 85th minute and Buddies' recent signing Collin Quaner limped off shortly after making his debut from the bench.