5 biggest upsets in cup competitions this season

#4 Nottingham Forest 4-2 Arsenal (FA Cup third round)

Forest knocked Arsenal out of the FA Cup

What was supposed to be a routine night for Arsenal turned into a six goal thriller and a defeat at the hands of Nottingham Forest in the third round of the FA cup. Arsenal fielded a young eleven consisting of Maitland-Niles, Joe Willock and Reiss Nelson. Danny Welbeck started up front.

Eric Lichaj gave the home side the lead with a close range header following a set piece. Their joy was cut short as Per Mertesacker equalised as he reacted first to a loose ball in the box after Rob Holding hit the post. Ospina had to make a crucial save as he denied Brereton a chance to make it 2-1. Forest eventually took the lead before half-time as Lichaj scored again with a well measured shot from outside the box.

Arsenal's misery continued into the second half as Holding gave away a cheap penalty and Brereton scored from the spot to make it 3-1. Welbeck gave Arsenal a lifeline in the 79th minute when he scored following an error from Forest keeper Jordan Smith.

Arsenal were piling on the pressure but another penalty was awarded to Nottingham as Debuchy brought down Traore in the box. Keiran Dowell stepped up to score the penalty and make the score 4-2. Forest defender Joe Warral was sent off in the 89th minute for a second yellow but Arsenal had little time left to salvage anything.

The damage was done and the current holders of the trophy were knocked out in the third round.