Forest beat Arsenal 4-2 at the same stage in 2018.Arsenal lost to Nottingham Forest in the FA Cup third round for the second time in four years thanks to Lewis Grabban's late strike.
The visitors were passive throughout and were deservedly beaten at the City Ground.
Mikel Arteta made numerous changes to his line-up but there was still a strong core to his team.
Bukayo Saka, Martin Odegaard and the in-form Gabriel Martinelli were among those in the side.
Forest, who beat the Gunners 4-2 at the same stage in 2018 and who have not lost a home tie in six years, were physical from the start.
Debutant Kienan Davis, leading the line after completing a loan move from Aston Villa, caused problems for the visiting defence during a first half in which Arsenal failed to assert themselves.
Arteta's frustration was illustrated when he substituted left-back Nuno Tavares for Kieran Tierney after 34 minutes, with the Portuguese defender throwing his gloves away and refusing to acknowledge his manager on the sidelines.
Visiting keeper Bernd Leno denied Philip Zinckernegal when he connected with Brennan Johnson's cross then kept out Joe Garner's free kick.
But with eight minutes left, substitute Grabban met another Johnson cross, and this time it found the net to condemn Arsenal to another third-round exit in the East Midlands.
Line-ups
Nottm Forest
Formation 3-4-3
30Samba
4Worrall27S Cook26McKenna
2Spence22Yates37Garner8Colback
20Johnson9Davis11Zinckernagel
30Samba4Worrall27S Cook26McKenna2SpenceBooked at 78mins22Yates37Garner8Colback20Johnson9DavisSubstituted forGrabbanat 68'minutes11ZinckernagelBooked at 35minsSubstituted forRibeiro Diasat 75'minutesSubstitutes
1Horvath3Figueiredo7Grabban10Carvalho13Bong18Ribeiro Dias19Costa Silva21Ojeda33TaylorArsenal
Formation 4-2-3-1
1Leno
17Cédric Soares4White16Holding20Tavares
23Sambi Lokonga87Patino
7Saka8Ødegaard35Martinelli
30Nketiah
1Leno17Cédric SoaresSubstituted forKolasinacat 90+1'minutes4White16Holding20TavaresSubstituted forTierneyat 35'minutes23Sambi Lokonga87PatinoSubstituted forLacazetteat 69'minutes7Saka8Ødegaard35MartinelliBooked at 74mins30NketiahSubstitutes
3Tierney9Lacazette21Chambers22Marí31Kolasinac32Ramsdale58Biereth65Oulad M'hand82HutchinsonReferee:Craig PawsonAttendance:24,938Live Text
Match ends, Nottingham Forest 1, Arsenal 0.
Second Half ends, Nottingham Forest 1, Arsenal 0.
Substitution, Arsenal. Sead Kolasinac replaces Cédric Soares.
Martin Ødegaard (Arsenal) wins a free kick in the defensive half.
Foul by James Garner (Nottingham Forest).
Attempt blocked. Lewis Grabban (Nottingham Forest) right footed shot from outside the box is blocked. Assisted by Cafú with a through ball.
Corner, Arsenal. Conceded by Scott McKenna.
Bukayo Saka (Arsenal) wins a free kick on the right wing.
Foul by Jack Colback (Nottingham Forest).
Goal! Nottingham Forest 1, Arsenal 0. Lewis Grabban (Nottingham Forest) right footed shot from the centre of the box to the bottom left corner. Assisted by Ryan Yates with a cross following a fast break.
Offside, Nottingham Forest. Djed Spence tries a through ball, but Brennan Johnson is caught offside.
Bukayo Saka (Arsenal) wins a free kick in the defensive half.
Foul by Jack Colback (Nottingham Forest).
Djed Spence (Nottingham Forest) is shown the yellow card for a bad foul.
Kieran Tierney (Arsenal) wins a free kick on the left wing.
Foul by Djed Spence (Nottingham Forest).
Foul by Bukayo Saka (Arsenal).
Jack Colback (Nottingham Forest) wins a free kick in the defensive half.
Substitution, Nottingham Forest. Cafú replaces Philip Zinckernagel.
Gabriel Martinelli (Arsenal) is shown the yellow card for a bad foul.
Watch five third-round ties live across the BBC including Manchester United v Aston Villa - plus highlights from every match (UK only). Read the full details here.
