90 minutes of football at the Emirates Stadium this afternoon were enough to comprehensively encapsulate exactly what has gone wrong at Arsenal over the past 12 years. After starting relatively comfortably in the first half, the second half was one to forget for the Gunners as goals from Odion Ighalo and Adlene Guedioura were enough to send Watford to Wembley stadium for the FA Cup semi-final, despite a late goal and some last-gasp drama from Danny Welbeck.

As the current holders are now eliminated and virtually have nothing to play for Arsene Wenger is now under immense pressure, and has probably never seen the depths of fan despair and anger quite reach this level during his 20 years at the club.

Arsenal are out, Watford go marching on, and Arsene Wenger - as well as the board - will be left pondering their next moves as Barcelona await in the Champions League.

Here are the five things we learned from Watford's 2-1 win over Arsenal.

Gabriel's a lucky boy

In a extremely uneventful first half, where Olivier Giroud was once again caught offside after hitting the back of the net, the main talking point from the first 45 minutes was Gabriel's overly aggressive two footed tackle on Watford captain Troy Deeney. The former Villarreal centre half jumped with both feet in order to win the ball but caught Deeney instead - potentially breaking his leg. The tackle went unpunished as referee Andre Marriner did not deem it dangerous enough to warrant even a free kick.

As we saw yesterday, Diego Costa was sent off for a 'kiss' on Everton Gareth Barry and Barry confirmed after the game that Costa did not bite him. If that warrants a sending off then Gabriel should be banned for at least five games....

A top striker is needed at Arsenal

Despite defeat and dishonourable discharge from the FA Cup, Arsenal missed a plethora of chances in the game and could've scored five or six goals if they had been more potent in front of goal. This is becoming a habit for the Gunners and is the fundamental reason why their title charge has once again taken a step back and the best they seem capable of is another top four finish - which presumably Arsenal fans will celebrate as wildly as they always do!

Guedioura scored the best goal of the FA Cup

So far in this 2015/2016 campaign, we have seen some sublime goals in the FA Cup. Dimitri Payet of West Ham was a prime example of that in the Hammers last FA cup game away at Championship outfit Blackburn Rovers with a sublime free kick and solo goal for his brace.

However, Watford midfielder Adlene Guedioura scored an absolute rocket of a strike, leaving Gunners Colombian shot stopper David Ospina with no chance and the goal was worthy of winning any cup tie. As his Twitter handle suggests, we may as well start calling him Pep!

Welbeck forced his way in England Euro 2016 squad

Arsenal forward Danny Welbeck has been out for the majority of the season with a knee injury and has recently come back into the first team fold. After notching the winner in the Gunners 2-1 victory over Premier League leaders Leicester City a fortnight ago, Welbeck scored another against Watford today, and his presence up front caused all sorts of problems for the Hornets' defence over a very nervy last few minutes. It was a good impact performance from the England man, though his misses were reminiscent of Arsenal's attacking play over the last few months of the season, even in Welback's absence.

We are all aware that England manager Roy Hodgson is a big fan of Welbeck and despite barely featuring this season as a result of his injury problems, Welbeck is almost certain to be on the plane to France for Euro 2016... barring another injury!

Wenger has lost his touch

With the title hopes virtually dashed - Arsenal are now eight points behind - the impossible task of overturning a 2-0 scoreline against FC Barcelona, and now being knocked out of the FA Cup, the 'Wenger Out' brigade has once again found its voice - and Wenger is feeling the full force.

Wenger's reluctance to buy a top class striker as well as a box-to-box midfielder has caused a stir amongst anyone remotely associated with Arsenal. With this latest defeat, it could be time for the Gunners to open a new chapter without Wenger, their boss for the last 20 years, but one who has only won two trophies in the last decade.