Defender Connor Ogilvie scored an 89th-minute winner as Gillingham beat out-of-form Sunderland at Priestfield.
Young Saints duo Alfie Jones and Tom O'Connor, who were both deployed in central midfield, played the entirety of the tie as left-back Ogilvie fired home a late winner for Steve Evans' side.
The win lifts Gills into 14th, a comfortable 10 points clear of the drop zone.
Forward Jake Hesketh played 88 minutes of Lincoln City's 2-0 success over Burton Albion - their first win in six League One matches.
Harry Anderson headed the visitors in front, before substitute Tyler Walker wrapped up victory for the Imps in stoppage time, firing in after more good work from Anderson.
Elsewhere, Marcus Barnes played 45 minutes of Eastleigh's 1-1 draw with Ebbsfleet, while Harrison Reed has been ruled out of action for Fulham through injury - they lost 2-1 at home to high-flying Bristol City.
In Scotland, Celtic picked up their tenth consecutive domestic trophy on Sunday afternoon, much to the heroics of loanee goalkeeper Fraser Forster, who saved a penalty during the 1-0 win over Rangers - Christopher Jullien's goal settled a dramatic final in the 60th minute. Moi Elyounoussi also played his part on the left wing.
In Europe, Wesley Hoedt was involved in Antwerp's 4-0 success over Waasland-Beveren, while Guido Carrillo was a second-half substitute in Leganés' 3-2 win against Celta Vigo.