It was the visitors who made the brighter start, Chris Zebroski volleying wide a teasing Scott Rendell cross early on.
But the hosts took the lead after 15 minutes with a goal of real quality - Furlong heading John O'Flynn's deep cross back across goal for Lee Sawyer to acrobatically volley home.
And it was O'Flynn that could have increased the lead when he shot inches wide after confusion in the Gulls' penalty area. Things got little better after the break and there was barely an attack of note as both sides struggled to find any fluency.
It was Torquay that did most of the pressing, with substitute Sam Cox coming the closest with a long-range drive before Furlong's intervention.