However, Hendon left only 18 days later when he was offered the role of Hessenthaler's assistant at Priestfield and was promptly followed by senior player Nicky Southall and youth team coach Darren Hare.
The hosts made a bright start but the Whites grew in confidence with Elliot Charles flashing a header wide before Birchall found the top corner with his superb strike.
I'Anson converted the rebound after Harry Baker's shot had been parried to make it 2-0 with the home side in disarray.
Gillingham took the game to their manager's former side in the second half but found the Dover defence and keeper Flitney in fine form.
Flitney had postponed an operation so he could feature in the tie and headed straight back to hospital after the game.
Dover chairman Jim Parmenter told BBC Radio Kent "I've been saying since August we'd get our compensation when we met Gillingham in the first round of the FA Cup and it's come true.
"I got the venue wrong - I said we'd get them at home, but we've gone on and beaten them 2-0 away. There was only one side out there that looked the better side and that was Dover for 90 minutes.
"We filled the away end of Gillingham. Fantastic support for the town, these people have suffered a lot over the last five or six years and now this is what they deserve and I'm absolutely delighted for the fans, the players and for Martin."
Dover goalkeeper Ross Flitney told to BBC Radio Kent:
"I'm going straight to hospital tonight for an operation on my neck and knee - bit of an infection which I've picked up in the week.
"I was in hospital last night. I put the operation off last night so I'll be back there this evening trying to get right for Tuesday."
Live text and stats
Saturday, 6 November 2010
The FA Cup
03 Nutter red card
15 Lawrence (Payne 42)
12 Palmer (Inkango 76 yellow card)
17 Spiller yellow card
21 Oli (Akinfenwa 20)
05 Schulz (Aisien 85)
11 Long (Wallis 83)
09 Charles (Hunt 37)
Ref: DeadmanAtt: 7,475
Attempts on target
Attempts off target
93:05 The referee blows his whistle to end the game.
90:00+1:37 Bruce Inkango challenges Jon Wallis unfairly and gives away a free kick. Direct free kick taken by Luke I'Anson.
90:00+1:37 Booking Bruce Inkango goes into the referee's book.
90:00+0:16 Corner from the right by-line taken by Danny Spiller, save by Ross Flitney.
89:35 Outswinging corner taken right-footed by Danny Spiller from the right by-line, Matt Fish makes a clearance.
87:59 Inswinging corner taken right-footed by Danny Spiller played to the near post, Jon Wallis manages to make a clearance.
86:57 Free kick awarded for an unfair challenge on Harry Baker by Barry Fuller. Ross Flitney takes the direct free kick.
85:43 Stefan Payne is adjudged to have handled the ball. Matt Fish restarts play with the free kick.
84:28 Substitution Olly Schulz goes off and Bobby Aisien comes on.
82:39 Substitution Sam Long goes off and Jon Wallis comes on.
82:27 Ben Hunt produces a right-footed shot from outside the penalty box and misses right.
77:59 Foul by Luke I'Anson on Danny Spiller, free kick awarded. Free kick taken by Alan Julian.
77:23 Nicky Southall concedes a free kick for a foul on Adam Birchall. Free kick taken by Thomas Wynter.
75:46 The referee blows for offside. Free kick taken by Ross Flitney.
75:02 Substitution Chris Palmer leaves the field to be replaced by Bruce Inkango.
74:44 Effort from a long way out by Harry Baker goes wide right of the goal.
74:01 Corner taken by Sam Long, clearance made by Nicky Southall.
72:28 Stefan Payne is penalised for handball and concedes a free kick. Direct free kick taken by Matt Fish.
71:45 Sam Long takes the outswinging corner, Header on goal by Olly Schulz from inside the box goes harmlessly over the target.
69:39 John Nutter concedes a free kick for a foul on Harry Baker. Harry Baker has an effort direct from the free kick, Jack Payne
gets a block in.
69:39 Sent off The referee red cards John Nutter for professional foul.
68:43 Free kick awarded for an unfair challenge on Danny Spiller by Joe Tabiri. Direct free kick taken by John Nutter.
67:20 Unfair challenge on Adebayo Akinfenwa by Olly Schulz results in a free kick. Free kick taken by Chris Palmer. Shot from just
outside the box by Danny Spiller goes over the bar.
63:48 Corner taken right-footed by Harry Baker, Olly Schulz produces a header from inside the area that goes over the bar.
63:23 Chris Palmer concedes a free kick for a foul on Sam Long. Free kick taken by Matt Fish.
62:45 Free kick awarded for an unfair challenge on Jack Payne by Luke I'Anson. Direct free kick taken by Nicky Southall.
62:29 Free kick awarded for a foul by Matt Fish on Stefan Payne. Alan Julian restarts play with the free kick.
60:18 Long range effort from Jack Payne misses to the left of the target.
58:14 Stefan Payne takes the chance to get an effort at goal. Ross Flitney makes a save. Corner taken left-footed by Chris Palmer
from the left by-line, Ross Flitney makes a save.
57:57 Shot by Jack Payne. Save by Ross Flitney.
54:12 Corner taken right-footed by Nicky Southall from the right by-line to the near post, Matt Fish manages to make a clearance.
52:17 Corner taken by Nicky Southall.
51:53 Effort on goal by Stefan Payne from 12 yards. Ross Flitney makes a save.
51:09 Drilled right-footed shot by Adam Birchall. Alan Julian makes a save.
50:34 Outswinging corner taken right-footed by Nicky Southall from the right by-line, Olly Schulz makes a clearance.
49:24 Corner taken by Chris Palmer from the left by-line, Close range header by Tony Sinclair goes over the bar.
49:02 Shot from 25 yards from Nicky Southall. Save by Ross Flitney.
48:22 The referee blows for offside against Ben Hunt. Alan Julian restarts play with the free kick.
45:01 The second half has started.
45:00+0:48 The ref blows to end the first period.
45:00+0:47 Stefan Payne produces a right-footed shot from just outside the box that misses to the right of the target.
44:31 Outswinging corner taken right-footed by Harry Baker from the right by-line.
42:20 Foul by Thomas Wynter on Nicky Southall, free kick awarded. John Nutter restarts play with the free kick.
41:11 Substitution (Gillingham) makes a substitution, with Stefan Payne coming on for Matthew Lawrence.
39:45 Effort on goal by Ben Hunt from 25 yards. Blocked by Matthew Lawrence.
38:48 Matthew Lawrence fouled by Adam Birchall, the ref awards a free kick. Direct free kick taken by Tony Sinclair.
38:01 Harry Baker produces a right-footed shot from just outside the box that misses to the right of the net.
37:00 Substitution Ben Hunt replaces Elliott Charles.
33:45 Corner from the right by-line taken by Harry Baker, Tony Sinclair manages to make a clearance.
32:34 Unfair challenge on Olly Schulz by Danny Spiller results in a free kick. Ross Flitney takes the free kick.
32:34 Booking Booking for Danny Spiller for unsporting behaviour.
31:33 Danny Spiller takes the chance to get an effort at goal. Save made by Ross Flitney.
30:30 Adebayo Akinfenwa takes has a header from just inside the penalty box which clears the crossbar.
29:26 Adebayo Akinfenwa gives away a free kick for an unfair challenge on Rob Gillman. Ross Flitney takes the direct free kick.
29:09 Tony Sinclair fouled by Luke I'Anson, the ref awards a free kick. Alan Julian restarts play with the free kick.
28:19 Foul by Joe Tabiri on Danny Spiller, free kick awarded. The free kick is delivered left-footed by Chris Palmer from right
27:14 GOAL - Luke I'Anson:Gillingham 0 - 2 Dover Goal scored by Luke I'Anson from close in high into the middle of the goal. Gillingham 0-2 Dover.
26:38 Harry Baker has an effort at goal from 20 yards. Save by Alan Julian.
25:40 The official flags Elliott Charles offside. Alan Julian takes the free kick.
22:17 Free kick awarded for an unfair challenge on Nicky Southall by Joe Tabiri. Free kick taken by Alan Julian.
21:49 Unfair challenge on Adam Birchall by Jack Payne results in a free kick. Joe Tabiri takes the free kick.
19:59 Substitution Adebayo Akinfenwa comes on in place of Dennis Oli.
17:56 Assist on the goal came from Harry Baker.
17:56 GOAL - Adam Birchall:Gillingham 0 - 1 Dover Adam Birchall finds the net with a goal from long distance to the top left corner of the goal. Gillingham 0-1 Dover.
15:02 Unfair challenge on Elliott Charles by Danny Spiller results in a free kick. Free kick taken by Rob Gillman.
12:04 Free kick awarded for an unfair challenge on Elliott Charles by John Nutter. Free kick taken by Matt Fish.
9:39 Elliott Charles gives away a free kick for an unfair challenge on Barry Fuller. Free kick taken by Barry Fuller.
8:30 Dennis Oli produces a right-footed shot from just outside the penalty area that goes harmlessly over the target.
7:28 Unfair challenge on Dennis Oli by Thomas Wynter results in a free kick. The free kick is delivered right-footed by Nicky Southall
from right wing, clearance made by Matt Fish.
7:01 Tony Sinclair fouled by Elliott Charles, the ref awards a free kick. John Nutter takes the free kick.
6:42 Shot from 18 yards from Chris Palmer. Ross Flitney makes a save.
3:42 Joe Tabiri takes a shot. Barry Fuller gets a block in.
1:57 Adam Birchall concedes a free kick for a foul on Matthew Lawrence. Free kick taken by Alan Julian.
0:55 Corner taken right-footed by Harry Baker, Barry Fuller makes a clearance.
0:30 Foul by Jack Payne on Adam Birchall, free kick awarded. Free kick crossed right-footed by Sam Long from left wing, Alan Julian
makes a save.
0:00 The game begins.
Live text and data provided by The Press Association.
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