Barnsley became the first team into the draw for the FA Cup fifth round after a deserved victory at Southend.
Campbell-Ryce put Barnsley into the fifth round of the Cup
Jamal Campbell-Ryce's 20-yard first-half strike gave the Tykes only their second away win this season.
Barnsley keeper Heinz Muller denied Tommy Black on numerous occasions and turned in an inspired second-half performance to frustrate the Shrimpers.
Both sides had plenty of chances, with Tykes' Daniel Nardiello going close and Simon Francis denied for Southend.
Campbell-Ryce, who left Roots Hall last summer in a £175,000 deal, created a goal out of nothing in the 22nd minute.
With his back to goal on the left, he turned Lewis Hunt and unleashed a rising shot from just outside the box that beat Darryl Flahavan at his far post.
Southend dominated much of the second half, with Barnsley's best chance of extending their lead coming when captain Brian Howard shot just over from 25 yards.
The win was Barnsley's first away from Oakwell since they won at Southampton on 22
Southend boss Steve Tilson:
"We had a right go in the second half but the ball just did not drop for us and the keeper has made a couple of decent saves.
"Flavs (Darryl Flahavan) has not had a save to make apart from the goal, which was a fantastic strike from Jamal.
"We deserved to get something out of the game but players always come back to haunt you, though there was not much Flavs could do about it."
Barnsley boss Simon Davey:
"Fair play to Southend, they put us under some pressure but I didn't think
they were going to score.
"I said to Jamal before the game make sure it is a happy return, make it happen for yourself and he has more than done that with a great goal.
"Now we want a big club, we want it at home in front a big crowd."
Southend: Flahavan, Hunt, Clarke, Barrett, Hammell, Francis, Bailey, McCormack, Gower, Hooper (Barnard 64), Black.
Subs Not Used: Collis, Maher, Liptak, Moussa.
Barnsley: Muller, Van Homoet (Kozluk 61), Foster, Souza, Tininho, Campbell-Ryce, Hassell, Ricketts (Togwell 61), Howard, Nardiello (Odejayi 73), Ferenczi.
Subs Not Used: Coulson, Leon.
Booked: Van Homoet, Nardiello, Campbell-Ryce.
Goals: Campbell-Ryce 22.
Ref: Paul Taylor (Hertfordshire).