Arsenal moved into the Premier League top four but made hard work of seeing off 10-man Watford 1-0 thanks to Pierre-Emerick Aubameyang’s fortunate early opener on Monday.
Aubameyang profited from an error by Watford goalkeeper Ben Foster as he blasted an attempted clearance in off the Gabon international.
Watford captain Troy Deeney was then shown a straight red card after just 11 minutes, but the Gunners failed to make the most of their man advantage and were fortunate as the hosts twice hit the woodwork.
However, Unai Emery’s men held out for a first clean sheet away from home in the Premier League this season to move ahead of Chelsea on goal difference into fourth.
Arsenal also edges to within a point of north London rivals Tottenham and two clear of Manchester United in the four-way battle for the two remaining Champions League places behind Liverpool and Manchester City.
Firstly, Foster dallied as Aubameyang closed in to concede a comical opener.
And within seconds, Deeney was punished for an elbow into the face of Lucas Torreira.
Arsenal now has just three days to prepare for the second leg of their Europa League quarter-final away to Napoli and should have ensured an easier finish.