A sweetly struck goal in the 92nd minute by the Southend midfielder Jay Smith, his second of the match, ensured that whoever takes over from the caretaker manager, David Webb, at the end of this week, will inherit a side who still have a say in this season's FA Cup.
Smith's opportunism in this closely contested first-round replay rescued his side from the imminent prospect of becoming the fourth League representatives to have been beaten by Canvey in this competition within the last four seasons.
Until Smith's decisive intervention, which earned a home second-round tie with Lincoln City, Southend were facing extra time minus their defender Mark Warren, who was sent off for an 86-minute foul on Lee Boylan.
Several times during this derby between sides separated by just five miles of Essex coastline, the visiting fans chanted the name of the former Southend player who has been tipped to return as player manager tomorrow, Stan Collymore.
But Webb, who confirmed that this was the last match of his two week stand-in period following the dismissal of Steve Wignall, sounded a warning note about the wisdom of appointing a man whose meteoric playing career will mean little if he finds himself in charge of a side struggling to preserve their League status at the bottom end of the Third Division.
"Whoever gets the job will need to give 100 per cent to improve the League position and I think it's going to take someone with experience. Someone without experience would have a lot of burdens on his shoulders," Webb said.
"I know the crowd were chanting Stan's name, but the club have got to be careful. It would be nice if someone could come in and just get Stan back playing for Southend - that would be the dream."
Canvey's dream this season relates to another competition - they are desperate to move up to the Conference and currently hold a big lead in the Ryman League.
This defeat, albeit sweetened by a fee of around £50,000 for live transmission rights on Sky TV, was hard to take against local rivals who also put Canvey out of the FA Cup three seasons ago.
Twice ahead through a Boylan header and then Geoff Minton, who rounded the keeper to score a breakaway goal with virtually the last kick of the first half, the home side were still never able to maintain a steady grip on the match.
Southend equalised first through Tes Bramble, who got the final touch on Leon Cort's towering header from a corner and then through a Smith shot a minute into the second half.
"Our boys were magnificent," Jeff King, the Canvey manager, said. "But we never thought we'd win the FA Cup. We've got to win our league."
Canvey Island: (3-5-2): Potter; Ward, Chenery, Theobald; Midgeley, Kennedy, Minton, Gooden (Dobinson, 74), Duffy; Gregory, Boylan. Substitutes not used: Berquez, Cowan, McDougald, Harrison.
Southend: (4-4-2): Flahavan; McSweeney, Cort, Warren, Stuart; Gower, Maher, Smith, Jenkins; Corbett, Bramble. Substitutes not used: Emberson, Broughton, Wilson, Constantine, Clark.
Referee: T Kettle (Maidenhead).Reuse content