Substitute Sam Cosgrove's stoppage-time winner ensured Plymouth stay top of Sky Bet League One following a 2-1 success over third-placed Sheffield Wednesday.
Cosgrove, who hit the crossbar minutes earlier, made no mistake with a bullet header at the near post to meet Niall Ennis' cross.
Scottish striker Ryan Hardie put Argyle ahead with a superb third-minute strike on the run after latching onto a Finn Azaz through ball.
The Argyle number nine took the ball in his stride and powered a diagonal strike into the corner past David Stockdale.
The Owls responded, with Tyreeq Bakinson putting Liam Palmer in on goal and his left-foot strike flew past home goalkeeper Michael Cooper after seven minutes.
Stockdale did superbly well to keep out Morgan Whittaker's goal-bound 37th-minute shot, while Cooper denied Michael Smith at full stretch.
Josh Windass beat Cooper in the 55th minute but his shot come back off a post, while the keeper had to be at his best to keep out a thumping Marvin Johnson strike after 64 minutes.
Both keepers had played superbly, with Cooper acrobatically keeping out a 71st-minute Palmer effort and Stockdale then denying Adam Randle in the next attack, but Cosgrove snatched the points with a last-gasp winner.