Mahlon Romeo's late strike was enough to win an evenly-contested FA Cup tie for Millwall against Southend.
The Shrimpers went close early on when Anthony Wordsworth's corner found Stephen McLaughlin charging into space, but he was denied by Ben Thompson's goal-line clearance.
Poor defending almost provided the breakthrough after 24 minutes, Steve Morison nodding on to Aiden O'Brien despite close marking, but his first shot was blocked before his second sailed over the crossbar.
The hosts returned the favour in the 34th minute, Shaun Hutchinson's loose first touch putting a hopeful punt forward into Simon Cox's lap but he scuffed his 25-yard effort well wide.
Neil Harris was given a half-time headache just before the break when Morison was stretchered off before the impressive Thompson took a nasty blow to the head and was unable to return.
Southend were sharp after the restart but rarely threatened, Ryan Leonard going closest with a 30-yard effort.
Goalkeeper Mark Oxley denied ex-Shrimper David Worrall after 77 minutes, before Hutchinson turned a dangerous corner narrowly over.
But Romeo was the hero two minutes from time, ghosting into the box before blasting beyond Oxley to snatch victory.