"WHEN we win, you say it's only the FA Cup," said Arsene Wenger after watching Arsenal bomb out of the competition at the hands of Watford. "So if we lose it cannot be an absolute disaster."

And yet for the home supporters who saw their team crumble at the hands of opposition that they expect to overcome, this clearly did feel like the gloomiest day of a season in danger of ending in a wreck. This defeat had a groundhog quality. You will probably be aware of the script: Arsenal look lively, dominate possession, create a few half chances, Giroud heads over the bar at lets once and then they are hit by sucker counter-attacks and lose the game. The only thing that was missing from the normal story today (Sunday) was a careless red card and a couple of players stumbling off with injuries.

Wenger admitted that his team did not make the most of a high share of possession and the early domination, but will enrage all but the most one-eyed fans by claiming that Arsenal did enough to win the tie. In truth, the Gunners only really came alive in the last eight minutes of play when sub Danny Welbeck coverted Mesut Ozil's flick and then missed the chance to complete an unlikely comeback by clattering a shot high and wide with the goal gaping after Alex Iwobi had struck the post.

But apart from those manic eight minutes Arsenal rarely seemed be awake to the fact that their two year unbeaten run in the FA Cup, as impressive as this record has been, was about to expire. Watford defended with strength and broke with pace and power. The thing that should hurt Gunners fans most is that they won without too many heart-stopping scares.  Odion Ighalo looked like everything Arsenal need up front, as he twisted and turned to score the opener 15 minutes into the second half. The Gunners defence had not for the first time in recent weeks switched off, and as the ball bobbled over from a throw in, Ighalo pounced.

With worryingly familiarity, Arsenal kept prodding the ball around from the 25 yard mark without really making any gains. A lot of forward moves fell apart when either Kieran Gibbs and, more so, Calum Chambers tried to support the attack. Chambers kept overhitting passes or falling out of step with the play.

As they reached for a way back into the match, Watford struck again with perhaps their best goal of the season. Adlene Guedioura's rocket was special but it was made possible by the muscle of Troy Deeney who held the play up for Watford and all day proved too tough for Per Mertesacker.

Wenger brought on Theo Walcott, Alex Iwobi and Welbeck. Giroud with two goals – both against Hull – in 12 matches had headed over once and almost scored at the near post with a reaction shot which Costel Pantilimon probably saved without actually realising how. But he was a disappointing spearhead and the onslaught from the subs only came when it was too late.

"It is very sad," said Wenger, who to avoid finishing the season empty-handed must now overturn Leicester's eight point advantage in the Premier League or, as he said, make "the impossible possible" against Barcelona in the Champions League next week. "But we are coming out of a very long run in the FA Cup. Today I think we did enough to win the match." He said he was not tempted to rest players in the Nou Camp to concentrate on the championship chase.

"This team has a great spirit," he said. "It has a very strong attitude. It's our job now to prepare them for the next match."

ARSENAL: Ospina, Gibbs, Chambers, Mertesacker (c), Gabriel, Coquelin, Elneny (Welbeck 68), Campbell (Iwobi 68) , Sanchez, Giroud (Walcott 68)
Subs not used: Monreal, Flamini, Bellerin, Macey