Arsenal, in Arsene Wenger's 21 years at the club had never failed to make it past the third round of the FA Cup but that record came to an end on Sunday as a 10-man Nottingham Forest side sent the holders packing with a comfortable 4-2 win at the City Ground.
Two first-half goals from two defenders off set-pieces saw both sides head for the tunnel at half-time all square.
Kieran Dowell's free-kick was fired in and Eric Lichaj
got in ahead of David Ospina to powerfully head in from close range but Arsenal turned the screw on their opponent moments later through Per Mertesacker
who reacted quickest to pounce on Rob Holding's deflected header off the woodworks to draw level.
Arsenal had to rely on David Ospina but the Colombian who appeared to be struggling with a finger injury had no answer for Lichaj's
and Forest's second in the closing stages of the opening period.
A poor header from Rob Holding and it fell to the American on the edge of the box who took it down on his chest and then produced a wonderful, arching volley that went into the top corner.Ben Brereton
doubled the home side's lead from the spot after a clumsy challenge from Rob Holding, who clipped Matthew Cash after a heavy first touch. The 18-year old forward deservedly put the ball past Ospina as Forest went 3-1 up. The Cup holders' hope were
revived inside the final 11 minutes, this time Danny Welbeck
who had been poor the entire period got lucky as a poor save by Smith dropped to the former Manchester United man to slide it into an empty net.
A controversial double kick by Dowell
from the spot following a foul on former Gunner Traore by Debuchy restored the home side's two-goal lead which was all Gary Brazil's men needed to see off their visitors.
This was Arsenal's first third-round defeat since losing to Sheffield United in 1996 and only their second defeat to Forest in our last 15 games.SETTING THE SCENE
Alex Iwobi returned to Arsenal's starting line-up after sitting out the 2-2 draw against Victor Moses' Chelsea last Wednesday.
Petr Cech made way for David Ospina who is yet to start a Premier League this season. Club captain Per Mertesacker partnered Rob Holding in the heart of the visitors' defense and were
flanked by Debuchy and Maitland-Niles.
Danny Welbeck led the attack for the Gunners with Southampton linked Theo Walcott getting the nod ahead of the regulars.
David Ospina made a good low save from Matty Cash on 20 minutes, but the keeper was beaten moments later from close range. Kieran Dowell whipped in a fierce free-kick from a tight angle, and Eric Lichaj arrived ahead of the keeper to get the final touch.
The lead lasted barely three minutes. Reiss Nelson won a free kick on the edge of the penalty box, which Walcott sent into a dangerous area. Rob Holding headed against the post but Mertesacker coolly controlled the rebound before stabbing home the equaliser
. It was the German's 10th goal for the club.
But as good as Arsenal looked going forward, the youthful Forest attack of Ben Brereton and Cash were causing problems at the other end. Ospina was called into action a couple of times to deny Brereton, but he could do nothing about the second goal.
Holding's headed clearance only fell to the edge of the box, and Lichaj let the ball bounce on his chest before sending it straight into the top corner. SECOND HALF
Wenger's men dominated possession in the early part of the second half, without creating any clear-cut chances, or working Jordan Smith.
But Forest soaked up the pressure and extended the lead from the penalty spot. Rob Holding upended Cash in the box, and for the third game in a row Arsenal conceded from the spot. The impressive Brereton dispatched the kick beyond Ospina.
Eddie Nketiah was immediately introduced and forced a smart save from Smith with a left-footed effort in the area.
Danny Welbeck gave the visitors a lifeline when he stroked home inside the area after Smith dropped the ball in the area.
Welbeck then had a penalty appeal waved away shortly afterward, but another moment of controversy ended Arsenal's bid to defend the trophy they won in May.
Jon Moss adjudged that Debuchy had fouled Armand Traore in the area. Dowell converted, but the officials missed the fact the spot kick was a double kick, and the goal was allowed to stand.
There was time for a late red card for Joe Worrall, and Walcott couldn't quite convert from close range, as the record-breaking 13-time FA Cup winners crashed out.