Published: 22:00, 19 November 2019
| Updated: 02:34, 20 November 2019
Brandon Hanlan fired Gillingham through to second round of the FA Cup.
His extra-time goal was enough to see off Sunderland at Priestfield in their first round replay.
Gillingham were the better side in the second half after an even first but the hosts were unable to test visiting keeper Lee Burge.
Referee Alan Young missed a blatant penalty in the first half of extra-time but Hanlan struck with 115 minutes played to win the tie.
Victory means the Gills will play Doncaster Rovers in the next round after they beat AFC Wimbledon 2-0 in a replay.
Weekend matchwinner Mikael Mandron missed out on facing his former club as illness ruled him out of the midweek replay.
It meant an enforced change upfront as Alex Jakubiak returned to the eleven.
Sunderland were missing a couple of starters from the original tie on international duty and rested others with niggles.
The opening 45 minutes was devoid of quality, with little goalmouth action at either end.
Gills made a bright start but Sunderland had the game’s first chance with Laurens De Bock glancing a header wide from Chris Maguire’s free-kick. Alfie Jones headed wide at the other end while well marshalled.
Brandon Hanlan had Gills’ two best chances of the half, heading Mark Byrne’s inviting cross wide and then seeing a deflected effort off Alim Ozturk go the wrong side of the post after leaving defender De Bock grounded.
The goalkeepers remained untested during the early stages of the second half.
Gillingham had penalty appeals ignored by the referee after Jakubiak’s powerful effort hit Ozturk, who went down holding his face, and there were half-hearted appeals when Olly Lee went to ground in the box during a good spell for the hosts around the hour mark.
In a game of few clear-cut chances, Will Grigg’s shot 20 minutes from time was about as close the game had come to a goal, firing just wide.
It needed a good clearance from Brandon Taylor as Hanlan looked to get on the end of Lee's cross. Alfie Jones headed the corner wide.
Byrne fired over for Gills with 10 minutes left and Hanlan had a shot blocked in stoppage time but normal time ended without a shot on target, for either side.
Hanlan headed over a Lee corner and the Gills were screaming for a penalty when Taylor handled Mark Byrne’s cross, but a goal did come.
Lee cross and Hanlan shot low past Burge, scoring just before the half-time whistle sounded for extra-time.
The Gills remained on top in the second half of extra-time to book their place in round two.
Gillingham: Bonham, Tucker, Fuller, Ehmer, Ogilvie, O’Keefe, Jones, Byrne, Lee, Jakubiak (Ndjoli 59mins), Hanlan. Subs not used: Walsh, Hodson, Charles-Cook, Cisse, Marshall, Pringle
Sunderland: Burge, Ozturk (Bainbridge 90mins), Power, Maguire, O’Nien, Watmore (McGeady 64mins), Grigg (Connelly 112mins), Leadbitter, De Bock, Hume (McGeouch 115mins), Taylor. Subs not used: Patterson, Sammut, Mumba.
Attendance: 3,561 (329 away)