Match ends, AFC Wimbledon 0, Millwall 1.
AFC Wimbledon 0-1 Millwall: Murray Wallace's winner sends Championship side through
Millwall defender Murray Wallace was labelled an "FA Cup hero" after he scored the winning goal for the second round in a row as the Championship side beat AFC Wimbledon to reach the quarter-finals.
Wallace, who also netted in the 94th minute against Everton, headed home in the fifth minute - moments after Joe Pigott had struck the post for the hosts.
But Pigott's close-range volley was as close as the League One strugglers came at Kingsmeadow, with the visitors looking more likely to add to their lead.
The result means Millwall can now look forward to a third quarter-final in seven years - and their second in the past three seasons.
"In the FA Cup you need heroes and Murray was that against Everton and he was again today," said Millwall boss Neil Harris.
AFC Wimbledon, who are bottom of League One, put in a spirited display but were unable to produce another upset after shocking Premier League side West Ham in the fourth round.
Millwall's position 28 places higher in the league pyramid just about told and Harris' team went close again when Aiden O'Brien toe-poked an effort straight at goalkeeper Aaron Ramsdale.
Jake Cooper also curled wide from outside the box for the Lions, who are in a relegation battle themselves and sit just two points above the Championship drop zone.
But the 2004 finalists are now just one win away from a semi-final spot and a trip to Wembley.
Millwall's FA Cup dream continues
Both of these teams headed into the fifth round having dumped top-flight opposition out at the previous stage, despite struggling in their respective divisions.
Millwall had failed to score in three games since beating Everton but netted with their first attempt on Saturday, as Wallace was left unmarked in the area to turn in Ryan Leonard's cross.
The visitors defended resolutely without really being tested and looked more likely to grab a second than concede, with the Dons' goalkeeper Ramsdale - on loan from Bournemouth - forced to make several smart saves.
The England youth international kept out O'Brien after the forward was played in by Lee Gregory, while also saving Leonard's side-footed effort.
Millwall's attention will return to trying to salvage their Championship status on Wednesday when they visit promotion hopefuls Derby, who were knocked out of the FA Cup on Saturday.
But boss Harris will surely believe there is a chance to continue their cup run this season, especially if they avoid a Premier League side in Monday's quarter-final draw.
"I said to players cup football suits us because of the way we play. It can be frantic - 100 miles an hour," he added.
"We would love to be at home, there's some good ties left in it and we will think we have half a chance. What an achievement for us to get here."
'Attention to detail' costs Dons
AFC Wimbledon boss Wally Downes said in the build-up to Saturday's tie that Millwall would provide an entirely different test to their surprise win over West Ham in the last round.
It was a test that got harder five minutes in when Wallace put the visitors ahead, with Downes saying his side's "attention to detail" let them down.
Had Pigott's front-post volley from Shane McLoughlin's dangerous cross squeezed in things might have been different for the third-tier outfit.
Their main outlet came down the right through 19-year-old wing-back Toby Sibbick, who went close himself with a deflected cross that looped on to the crossbar.
As it is, they return to League One action at Rochdale on Tuesday seven points adrift at the bottom of the table.
"We lost the opportunity of getting into a cup final but we have to approach every game as a cup final now," said Downes.
"There is no room for disappointment. The game will be reviewed on Monday - the players can sulk until then."
Man of the match - Toby Sibbick (AFC Wimbledon)
Millwall continue to be Dons' bogey team
- Millwall have reached the FA Cup quarter-finals for the third time in seven seasons - more than any other side from outside of the Premier League in that time.
- AFC Wimbledon have never beaten Millwall, drawing two and losing three of their five matches.
- The Dons have lost 13 home games this season, more than than any other side in the top four tiers of English football.
- Millwall have won two of their past four away games, having won none of their first 12 on the road this season.
- The Lions' Murray Wallace has now scored in back-to-back appearances in the FA Cup, after failed to find the net in his first 10.
- 8HartiganSubstituted forPinnockat 63'minutes
- 40WordsworthBooked at 69mins
- 12GarrattSubstituted forBarchamat 45'minutes
- 39PigottSubstituted forConnollyat 63'minutes
- 25WallaceBooked at 75mins
- 22O'BrienSubstituted forElliottat 65'minutes
- 9GregorySubstituted forHutchinsonat 90+3'minutes
- Jonathan Moss
- Shots on Target
Second Half ends, AFC Wimbledon 0, Millwall 1.
Substitution, Millwall. Shaun Hutchinson replaces Lee Gregory.
Adedeji Oshilaja (AFC Wimbledon) wins a free kick in the defensive half.
Foul by Tom Elliott (Millwall).
Corner, Millwall. Conceded by Mitchell Pinnock.
Anthony Wordsworth (AFC Wimbledon) wins a free kick on the right wing.
Foul by Shaun Williams (Millwall).
Attempt missed. Anthony Wordsworth (AFC Wimbledon) left footed shot from the right side of the box is high and wide to the left. Assisted by Shane McLoughlin with a headed pass.
Attempt missed. Anthony Wordsworth (AFC Wimbledon) header from the centre of the box is too high. Assisted by Mitchell Pinnock with a cross following a corner.
Corner, AFC Wimbledon. Conceded by Mahlon Romeo.
Attempt missed. Dylan Connolly (AFC Wimbledon) right footed shot from the right side of the box is too high. Assisted by Rod McDonald with a cross.
Corner, Millwall. Conceded by Shane McLoughlin.
Attempt missed. Ryan Leonard (Millwall) right footed shot from outside the box is close, but misses to the left.
Foul by Toby Sibbick (AFC Wimbledon).
Ryan Leonard (Millwall) wins a free kick in the defensive half.
Attempt missed. Lee Gregory (Millwall) header from the centre of the box is close, but misses to the left. Assisted by Jed Wallace with a cross.
Attempt saved. Ryan Leonard (Millwall) right footed shot from the centre of the box is saved in the centre of the goal. Assisted by Shane Ferguson.
Anthony Wordsworth (AFC Wimbledon) wins a free kick in the defensive half.
Foul by Lee Gregory (Millwall).