Northampton's opening day hoodoo continued despite their wealth of summer signings.
The Cobblers have not won on the opening day since 1995 but they were hot favourites to brush aside the injury hit Gulls, who listed last season's top-scorer Martin Gritton among their absentees.
But midfielder Jason Fowler shocked an expectant home crowd by snatching a 62nd-minute winner.
Fowler almost seemed uncertain what to do when he collected a pass from Kevin Hill on the edge of the box but he drifted a casual looking shot past Glyn Thompson in the home goal.
Torquay were lively on the break but hardly tested Thompson, although two minutes after the goal another shot from Fowler was deflected off the chest of David Woozley onto the post before bouncing back off Thompson and over the bar.
Gulls keeper Arjan Van Heusden pulled off a string of smart saves to deny three of the eight Northampton players who were making debuts after a busy summer in the transfer market for boss Martin Wilkinson.
Record signing Josh Low, Martin Smith and Marc Richards all went close but could not find a way past Van Heusden, while Low also saw a 36th minute shot cleared off the line by Lee Canoville.
Martin Wilkinson was understandably upset, but said: "I believe we will still get promotion this season. In a funny sort of way this comes as a bit of a relief. I went into a shop this morning and people were asking me whether we were going to win by six or seven goals." He added: "We should underestimate the strength of Division Three. This Torquay side played together for most of last season and we have only had six or seven weeks with these players." Gulls boss Leroy Rosenior said: "All of my players worked their socks off today and I thought we kept the ball well, especially in the second half."