Arsenal suffered one of the worst defeats of Arsene Wenger's reign as an abject 4-2 defeat at Nottingham Forest knocked the holders out of the FA Cup.
Wenger fielded a vastly weakened side for the third-round clash and the manager who has won the competition seven times suffered a big blow to his tenuous authority with the shocking exit to a young Forest side.
Eighteen-year-old Ben Brereton tormented the Arsenal defence and scored the third from the penalty spot after Eric Lichaj had scored twice, the second of which was a stunning looping volley.
Per Mertesacker had pulled one back to make it 1-1 but Arsenal were barely in the game. They needed a goalkeeper's mistake to make it 3-2 as Danny Welbeck profited but a Kieran Dowell penalty, awarded despite suggestions from Arsenal he had made contact twice while slipping as he shot, gave Forest the comfortable win they fully deserved.
Reiss Nelson looked dangerous and lived up to his billing as a player of some talent -- but that was it. Pathetic.
A shock exit to lower-league opposition is never a great look; doubly so when you've been comprehensively outplayed and possibly even deserved to lose by more. This was a defensive horror show and one of the real low points of Wenger's late reign. The FA Cup has sustained him when other competitions have brought disaster: not this year.
Manager rating out of 10
1 -- You could understand the compulsion to rest players at a busy juncture of the season but this was a rotation or five too far. Wenger, exiled to the stands, picked a bad team, set them up in the wrong formation, failed to do anything about Forest's obvious domination in the first half and then couldn't turn the game with his changes either. One of his worst days as boss.
Player ratings (1-10; 10=best. Players introduced after 70 minutes get no rating)
GK David Ospina, 6 -- Ospina made a succession of superb saves in the first half to keep the score down but nevertheless looked exposed for the opening goal. Maintained Arsenal's proud record of being utterly incapable of saving penalties.
DF Mathieu Debuchy, 3 -- Got a bit of a chasing in the first half as Forest took Arsenal apart at will and then gave away the second penalty -- even though it looked like he might have got the ball. Shouldn't really be at the club.
DF Per Mertesacker, 3 -- The captain got Arsenal level with a smart finish from the six-yard box but Mertesacker struggled badly with the movement of young Brereton. Looks a spent force.
DF Rob Holding, 4 -- Played his part in the Mertesacker goal as it was his header which came off the post. But gave away the penalty with a mistimed challenge. Laboured in the second half.
DF Ainsley Maitland-Niles, 5 -- Was turned too easily in the build-up for Forest's second but otherwise his link-up play was good. Worth persisting with.
MF Joe Willock, 4 -- Was caught out too often in the first half as he struggled a touch with the pace of the game. Understandably taken off following the third goal.
MF Mohamed Elneny, 5 -- Had to give more to the team as one of the more senior players.
FW Theo Walcott, 4 -- Was a lively presence early on but, to no surprise, lacked a clinical edge. He could have scored on seven minutes but scuffed wide after a lovely move. Offered far too little.
MF Alex Iwobi, 4 -- A disappointment. Has to be dominating games like this if he is to be a big player.
FW Reiss Nelson, 6 -- Playing in an advanced position on the left, Nelson was a constant threat and won the free kick for the Mertesacker goal after being fouled after a sweet nutmeg.
FW Danny Welbeck, 5 -- Got lucky when Jordan Smith spilled the ball at his feet for the second goal. Could have done more.
FW Eddie Nketiah (for Willock, 65), 6 -- Denied by a smart save soon after his introduction and Smith kept out a second effort late on. Made an impact at least.
FW Chuba Akpom (for Debuchy, 87), NR -- What is the point, really?