Zebroski pounces for Robins
Zebroski latched onto a throughball from central defender Harry Hooman to clinch a share of the spoils.
Torquay target man Rene Howe had headed 2-1 ahead in the 23rd minute from a deep cross from the left by home skipper Lee Mansell.
Howe's goal came a minute after central defender Aaron Downes had marked his home league bow by powering home a header from Kevin Nicholson's free-kick.
Howe had an opportunity to double his tally in the 65th minute but his close-range shot came back off the post and his back heeled follow-up was cleared off the line by Hooman.
Hooman had set up striker Matt Harrad's 15th minute opener, headed in on the line, following a corner.