There was nothing tepid about this fiery contest in Dingwall, but Melvin De Leeuw was true to the adage as he delivered a chillingly late killer blow.
Tempers then exploded in the final minutes after a Jim Goodwin head clash with De Leeuw, an incident which lead to both managers Derek Adams and Danny Lennon being packed off to the stand following an angry exchange.
Adams evidently felt the act was pre-meditated. Lennon clearly disagreed, as did referee Willie Collum who kept his cards in his pocket as he did during a similar first half incident between Goodwin and Filip Kiss.
It was perhaps understandable that emotions should run high. St Mirren's fifth straight defeat saw County leapfrog them into ninth place, while Partick Thistle's victory over Aberdeen had the men from Paisley plummeting into the dreaded play-off spot.
In fairness, it was a game County deserved to win, but one where wastefulness in front of goal might easily have cost them dear. On-loan Notts County striker Yoann Arquin headed the opener seven minutes before the break, but, in an otherwise strong display, was to pass up three more decent chances. County defender Yann Songo'o also blew two in front of goal, allowing John McGinn to fire St Mirren level against the run of play.
It fell to De Leeuw, however, to emerge with the last laugh with a fine finish near the end. "I scored the winning goal and it was a good feeling to do that in the circumstances," said the 25-year-old former SC Cambuur striker.
"It was an unfair challenge (by Goodwin), and not just because it was on me, I was unhappy about that one and the one on Filip Kiss in the first half."
Head-butt allegations aside, it proved an open, attacking game, with both clubs opting for adventure over caution, but County's failed attempts at goal were piling up thick and fast in the first half so the breakthrough after 38 minutes was deserved on the law of averages. Michael Tidser won the ball from Eric Djemba-Djemba in the thick of midfield and then took a return pass from Jordan Slew. Tidser's cross from the left was met by an Arquin header that looped behind Marian Kello for the opener.
After the break, County regained the initiative and should have doubled the lead almost immediately, but Kello twice defied Slew and Arquin.
County were made to pay after 65 minutes when Gregg Wylde's corner was half cleared by Erik Cikos. John McGinn collected and drove past two County men across the edge of the box and from just inside the area, buried a fine shot high past Mark Brown.
But the final act in the drama came when Arquin slid the ball across for De Leeuw to execute with a measured shot into the roof of the net from 12 yards. Saints' manager Lennon was disappointed with himself for being dragged into the touchline fracas over Goodwin. "It's a passionate game. Derek wants the best for his side, I want the best for mine. Nothing more than that," he said. "That's Jim's game. He competes fantastically well."
As for his own dismissal, Adams said."It was a big game for both sides and emotions ran high. But Danny and I had a cup of tea and coffee afterwards and there is not a problem. It's the nature of the business we're in."