Manager Danny Heale handed a full debut to new central defensive signing George Allen. Jake Pitty dropped to the bench and Steve Sheehan took his place at right back. Omarr Lawson and Callum Ibe were also brought into the side at the expense of Harrison Chatting and Martin Tuohy.
Canvey took the lead on 16 minutes when a dangerous cross from Frankie Merrifield found George Allen at the back post who was able to head home into an unguarded net.
However, the Gulls were only in front for two minutes when a free kick from distance caught out the Canvey defence and was converted from close range by Steve Brown.
Callum Ibe thought he had opened his account for the club on 40 minutes, but his goal was ruled out as the flag for offside had been raised against the forward.
A minute later Omarr Lawson had a shot saved by Harrow keeper Brendan Hazlett, but George Sykes was on hand to turn the rebound back towards goal. However, his effort rolled along the crossbar before being scrambled clear by the home defence.
Canvey went close twice in the second half with long range efforts from George Sykes and Omarr Lawson, both of which narrowly missed the target.
Harrow could have won the match with eight minutes to play from a corner, but thankfully the ball was scrambled clear before a red shirt could turn the ball home.