Alex Fisher's stunning stoppage-time equaliser denied Southend a first win of the campaign and earned Exeter a 2-2 draw in League Two.
The Shrimpers seemed to be heading for their first win under manager Mark Molesley when Jason Demetriou put them back in front from the penalty spot.
But Grecians substitute Fisher scored a brilliant effort five minutes into stoppage time to secure the visitors a share of the spoils.
Southend broke the deadlock in the 26th minute with Brandon Goodship drilling a low 20-yard shot into the bottom right corner of the net.
Exeter equalised in the 40th minute with Joel Randall firing home a pass from Ryan Bowman.
Southend regained the lead 20 minutes into the second half, with Demetriou making no mistake from the spot after Tottenham loanee Kazaiah Sterling had been brought down by defender Lewis Page.
But Exeter hit rescued a point deep into added time, with Fisher firing into the top left corner of the net from 25 yards as Southend's winless start to the season stretched to an eighth game in all competitions.