However, Success was refreshingly enthusiastic when asked if Watford could go all the way.

He told the club's official website, www.watfordfc.com: "It's possible, nothing is impossible. We just have to keep going, working hard like this and approach each game as it comes game by game."

Gracia's entirely new team made a better fist of it than their hosts, who were dreadful throughout, although it was all relative and apart from a few flashes of brilliance from midfielder Will Hughes, there was little to excite the crowd.

It was Hughes' astute 62nd-minute pass which allowed Andre Gray to open the scoring, and he was involved again at the death in the move from which Success wrapped up the win.

He said: "It was a good game for us, 11 changes – it's not an easy decision for the coach, but he has so much confidence in the players and we're happy about that.

"We are working hard and we're happy to proceed to the next round."

If there was satisfaction with a job well done as the visitors headed back to Hertfordshire, the gloom which has engulfed Tyneside in recent weeks turned a shade darker.

A fan-base at war with owner Mike Ashley has not seen the club progress past the fourth round since the year before he bought the club in 2007 and the visit of a much-changed Watford side seemed the perfect opportunity for the six-times winners to address that failing.

Instead, Benitez made a point with his team selection – the point being that his squad is not big enough or strong enough to compete for anything other than Premier League survival – as his mounting frustration at the club's less than effective recruitment strategy reached new heights.

In the event, supporters who turned up hoping for a little light relief left wondering what might have been as the Spaniard kept his powder dry for Tuesday night's league clash with champions Manchester City, a game in which he knows they could turn in their best performance of the season and still lose comfortably.

However, Benitez was unrepentant.

He said: "The fans, they know, so it's not that I have to explain every time the situation. We put a team on the pitch that could win, we didn't do it and that proved that we have to just concentrate on one competition."

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