Walsall were forced to dig deep to see off a determined Southend 2-1 at Roots Hall in the Capital One Cup.
Kieron Morris' late strike secured a second round slot for the Saddlers but only after Dean Smith's side had withstood sustained spells of pressure from the Shrimpers.
Walsall went in front in the 25th minute when Mal Benning fired home Andy Taylor's left-wing cross.
Southend equalised in the 68th minute when Ryan Leonard slammed home a stunning 25-yard shot.
Shaq Coulthirst then came close to putting the league Two side in front with an effort which fizzed just past the right-hand post and Walsall goalkeeper Richard O'Donnell also pulled off a stunning save to somehow keep out a header from Luke Prosser.
But Walsall survived the scares and grabbed victory with three minutes remaining when substitute Morris collected the ball on the edge of the penalty and impressively fired in to the roof of the net with his left foot.