Stephen Langford staked the visitors to the early lead, beating Sudbury starter Michael Muzyka 1:35 into the contest.
Special teams allowed the Nickel Barons to pull level before the opening period was complete with Andre Comtois scoring on the power play at 16:24.
North Bay regained the lead in the latter stages of the middle frame as Braeden Pearl put the Trappers up 2-1 after 40 minutes.
After Cole Klippenstein’s man-advantage-marker made it a 3-1 game four minutes into the third, Comtois struck twice late in regulation to cap off a hat trick and force extra time, including a shorthanded equalizer with 2:34 to go.
Following a scoreless first five-minute OT session, the two teams went to the second extra stanza where they played three skaters aside.
It was there that Leroux scooped up the puck in front of his bench and darted down the middle of the ice before stepping around a North Bay defender and stuffing the game-winner past Trappers affiliate netminder Sylvain Miron, who made his first appearance of the season.
Muzyka made 34 stops to register the win as the Nickel Barons snapped a four-game losing drought while improving to 10-8 overall.
Miron faced 39 shots in his debut as the Trappers picked up a point with the OT setback as their record went to 12-2-2-3. That allowed them to move into a tie for first place in the NOJHL standings with the idle Soo Thunderbirds at 29 points apiece. The T-Birds do hold two games in hand.