Roper scored early in the second half and then continued to play a leading role in helping Walsall to maintain their impressive record of not conceding a league goal at home this season.
They stretched the run to nine games but lived dangerously in the first half when Torquay were often the better side but still failed to get break their dismal run without a goal.
The Gulls are still without a goal in their last eight games during which time they collected just one point.
They were certainly a surprise packet against an off-key Walsall side that struggled to make an impact in the first period.
Referee Darren Deadman made his usual contribution with five bookings to take his tally after ten games to a massive 48.
Torquay may have gone off the boil since their early season flourish but they conspired to carve out numerous problems for a Walsall side that gave a frustrating display.
Jamie Ward was a persistent threat and the former Aston Villa player should have ended Torquay's recent goal drought in the first half when he had two good chances close to half time.
An uncertain Chris Westwood failed to make contact with a bouncing ball and Ward took advantage to gain possession only to hesitate and chip his shot over the bar as Clayton Ince advanced from his goal.
Walsall's attacking options were certainly limited with their two strikers Martin Butler and Hector Sam off the pace to such an extent that neither really troubled the brave Gulls keeper, Nathan Abbey.
Fortunately for the Saddlers Roper was in commanding form and did much to stifle Torquay's determined attempts to get onto the score-sheet.
He certainly made an even bigger impact at the start of the second half when he moved up for a Dean Keates corner in the 52nd minute and calmly headed home the opening goal and only his second of the season.
With Torquay looking for the equaliser they left gaps at the back which should have been exploited by Kris Taylor who wasted two good opportunities in the final two minutes.