Former Cambridge, Leicester and Coventry striker Benjamin, on loan from Peterborough, headed the Saddlers into a tenth minute, losing his marker and nodding home Kris Taylor's left-wing cross.
Benjamin was a real handful for young Torquay centre-half Chris Robertson, and five minutes later he was at the centre of a hotly disputed penalty decision.
Referee Phil Joslin ruled that Benjamin was pulled back by Lee Mansell in a crowded goalmouth, and Dean Keates made no mistake with the spot-kick for his 10th goal of the season.
Walsall wingers Taylor and Darren Wrack, in for injured duo Kevin Harper and Kevin Cooper, were a constant threat and it would have been all over if Wrack had hit the target, instead of firing a great chance wide from Taylor's cross in the 39th minute.
Walsall were good value for their interval lead, but it was a different story in the second half.
Torquay roared back and, after a sustained spell of pressure, cut the deficit in the 58th minute.
Young Reuben Reid, on loan from Plymouth, scored his second goal in two games with a shot on the turn from Matt Hockley's headed through-ball.
If Torquay had equalised during their best spell of the match, they might have gone on to cause an upset.
And they went close in the 63rd minute when Lee Thorpe pulled his six-yard shot wide across the face of goal when it looked easier to score after Reid had burst past two Walsall defenders.
With Walsall's keeper Clayton Ince and central defenders Chris Westwood and Anthony Gerrard all outstanding, the visitors held on to stretch their current unbeaten run to seven games.