Goals from Billy Bodin and Lee Mansell set Torquay United on their way to achieving their first league double over Plymouth Argyle since the 1970-71 season.
Swindon loanee Bodin gave the Gulls the lead on 58 minutes before captain Mansell added a second eight minutes later when he drilled home a pass from Danny Stevens.
Luke Young pulled one back for the Pilgrims with a headed effort on 72 minutes, but they could not force an equaliser as their five-match unbeaten run came to an end.
The result leaves Torquay two points off the Play-Offs and the Pilgrims three points from safety.