For almost 22 years, Arsene Wenger had never been knocked out in the third round of the FA Cup – until Sunday, when the FA Cup holders suffered their first third-round defeat and crashed out of the tournament after suffering a 4-2 defeat from second-tier Nottingham Forest in a sizzling City Ground clash.

The Gunners, fielding a much-changed side from the one that drew with Chelsea midweek and with manager Arsene Wenger watching from the stands because of a touchline ban, trailed 2-1 at halftime after Eric Lichaj scored twice.

At the end of the game, there were boos from some of the Arsenal fans after they watched their side concede four goals to lower-league opposition in the FA Cup for the first time since 1908. It was also Wenger's first taste of a third-round exit.

Lichaj headed in from close range after 20 minutes but the lead lasted only three minutes as Mertesacker finished well when the ball fell to him in the box.

American Lichaj produced a moment of magic to put Forest back in front just before the interval, chesting the ball down and looping a volley over keeper David Ospina.

Nottingham Forest players celebrate scoring. [Photo/VCG] 

Teenager Brereton sent Ospina the wrong way from the penalty spot after Rob Holding had fouled Matty Cash in the 64th minute.

Arsenal, missing a host of match-winners including Alexis Sanchez, Mesut Ozil and Aaron Ramsey, were thrown a lifeline with 12 minutes to go when England striker Welbeck punished a mistake by Forest keeper Jordan Smith.

Former Arsenal player Armand Traore was then brought down by Mathieu Debuchy as he surged into the box in the 84th minute and Forest was awarded another penalty.

Kieran Dowell converted but Arsenal players claim Dowell made contact with the ball twice, kicking it against his standing foot, but the referee decided the goal should stand.