Andy Hessenthaler's Gillingham were knocked out of the F.A Cup by his former club Dover Athletic at Priestfield Stadium.
The Blue Square Bet South side, 33 places below the Gills in the football pyramid, scored twice in the first-half to create one of the giant-killing shocks of the round.
The Gills did put Martin Hayes side under immense pressure in the second-half but once John Nutter received his marching orders in the 70th minute it was all but game over.
The Gills boss made one change to the team that were beaten by Wycombe in midweek - Nicky Southall, one of the management team that had been at the Crabble last season, came in for Adebayo Akinfenwa. The Gills coach took up a position on the right-side of midfield with Dennis Oli pushed up front in a 4-4-2 formation.
Before the game everyone in the ground perfectly observed a minutes applause for former Gillingham legend Bill Collins who sadly passed away in midweek.
Once the game got underway there was the expected frantic opening, Alan Julian had to punch clear a Sam Long free-kick and Joe Tabiri saw a powerful shot blocked by Barry Fuller at one end while at the other, Danny Spiller glanced a header at Ross Flitney, Chris Palmer fired a shot straight at the keeper and Oli blasted over the top. All this before ten minutes were on the clock.
Just as the pace seemed to ease for the first time, Dover took a 19th minute lead. Leading scorer Adam Birchall got the ball around 25 yards out and cracked home a terrific right-foot shot that flew past Julian. The large away support at the other end were delighted, to say the least!
Things got worse for the Gills when Dover went two up in the 28th minute. The excellent Harry Baker got away down the right and his shot was parried by Julian, Elliott Charles jumped for the rebound and seemed to handle as the ball dropped. Referee Darren Deadman didn't blow and Luke I'Anson was on hand to fire into the roof of the net.
The Gills responded well with Akinfenwa heading a Southall cross just over and Spiller having a rasping drive parried by Flitney and his follow up was blocked by ex-Gill Tom Wynter.
Spiller was then booked in the 33rd minute - going down rather easily on the edge of the area.
Charles who had been doubtful with a hamstring problem prior the game was forced to limp off in the 36th minute. He was eventually replaced by Ben Hunt.
Matt Lawrence limped off with what looked like a hamstring problem in the 42nd minute. Stefan Payne came on in his place and in the enforced defensive reshuffle John Nutter moved into central defence with Palmer reverting to left-back.
The Gills best effort of the half came from Stefan Payne in the three minutes added on, when he connected sweetly on the volley to a Spiller ball in but his effort flew just wide.
After an early second-half chance for Birchall, he fired a low shot at Julian, the Gills began to put the Whites under immense pressure.
Stefan Payne played a neat one-two with Akinfenwa but saw his fierce near post shot turned aside at his near post by Flitney. From Southall's resultant corner, Spiller rose high but headed straight at the keeper.
In the 59th minute, the tireless Jack Payne saw his 20-yarder parried by the outstanding Flitney and the keeper reacted quickly to beat out Spiller's follow-up.
Two minutes later it was Jack Payne again who went close again, drilling a low shot through the crowded area but inches wide.
Dover then went close in the 65th minute, Baker played in a corner from the left and Ollie Shulz rose highest but couldn't keep his header down.
A poor decision from referee assistant Matt Stewart cost Gillingham in the 70th minute. He failed to flag for offside as Baker burst through and when Nutter, without any covering team-mates clipped the winger to send him tumbling, referee Darren Deadman had little option but to brandish a red card.
The reshuffles continued with Southall dropping into defence, when Bruce Inkango was introduced in the 76th minute.
It wasn't long before the French winger was warming the hands of Flitney with a low shot but that was it as far as clean cut chances were concerned.
Even down to ten men the Gills were still going forward but the Dover defence was happy to soak up the pressure
At the final whistle it was no surprise that the Whites celebrated on the pitch with their 2,300 buoyant fans fans for a long time, cherishing their victory.
Everyone had said this was their cup final but it's Martin Hayes' outfit that go into the Second Round draw taking the £18,000 from the FA's prize fund with them.
To make matters worse it looks as if the Gills may well be down to the bare bones for next week's game with Crewe, both Spiller and Nutter will miss the game through suspension while the injured Matt Lawrence and Dennis Oli must be doubts.
Gillingham: Julian, Fuller, Lawrence (S Payne 42), Sinclair, Nutter, Oli (Akinfenwa 21), Spiller, Southall, J.Payne, Palmer (Inkango 76), McDonald.
Unused subs: Maher, Cronin, Miller
Dover Athletic: Flitney, Fish, Wynter, Tabiri, Schulz (Aisien 86), Gillman, Baker, I'Anson, Charles (Hunt 37), Birchall, Long (Wallis 83).
Unused subs: Norville, Cutler, Hook, Bah.
Attendance: 7,475 (2,300 Dover)
Referee: Darren Deadman
Assistants: Matt Stewart & Adrian Sannerude
Fourth Official: Barry Holderness