Shaq Coulthirst came off the bench and had an immediate impact by scoring the goal that settled Southend's tie with Portsmouth on Saturday.
Introduced in the 87th minute, the young striker scored three minutes later, striking a low shot past Pompey keeper Paul Jones as the Shrimpers ran out 2-0 winners.
Jordan Archer finally made his league debut for Northampton Town but was unable to stop them succumbing to a 3-2 defeat to Newport County.
The Cobblers were three down inside the hour mark but staged a comeback that came just short, much to the relief of Newport boss and ex-Spur Justin Edinburgh.
In the Championship, Alex Pritchard played 75 minutes in Brentford's 3-2 home win over Brighton, while Grant Hall was forced off with injury at half time in Birmingham's 1-1 draw against Leeds.
Tom Carroll stayed on the bench as Swansea lost 4-2 at Chelsea in the Premier League, and Kenneth McEvoy was an unused sub for Peterborough in League One, as the hosts played out a goalless draw against Notts County.
Lewis Holtby made his competitive debut for Hamberg but was on the end of a 2-0 loss, and will be playing under a new manager after Mirko Slomka was sacked following the defeat, and Grant Ward played 80 minutes and won a penalty - which was not converted - as Chicago Fire conceded late on and drew 1-1 with Toronto FC.