Proceedings were slow starting at Vicarage Road as neither teams threatened to apply pressure to each other’s goals in the opening stages.
As the game settled, it was the home side that seemed to take control, breaking several times from midfield to stretch Arsenal’s defence.
The first real chance of the game fell to Roberto Pereyra, whose touch on Abdoulaye Doucoure’s cross excited the home fans, but failed to provide Petr Cech with any work as the ball bounced away for a throw in.
Doucoure was Watford’s heartbeat in the opening minutes, as he has so often been this season, the Frenchman caused a sense of unsettlement among the Arsenal midfield, relishing against Arsenal’s early lacklustre midfield.
Arsenal on the attack
Arsenal too had their moments, Mohamed Elneny fired a venomous long range shot towards the goal of Heurelho Gomes. The Egyptians' strike dipped just over the crossbar without troubling Gomes.
The Gunners threatened again soon after, as they turned on their passing expertise on the counter. An exchange of passes between Hector Bellerin and Alex Iwobi sent Alexandre Lacazette towards the Watford box, the Frenchman showed his class as he scooped the ball over Adrian Mariappa’s attempted tackle before the ball was ushered away by Jose Holebas.
Watford’s luck soon ran out, as Arsenal captain Per Mertesacker gave his team the lead from a corner. A corner from Granit Xhaka found the head of the tall German who buried his first Premier League goal for four years.
First Half: 0-1
Shortly after the start of the second half, Danny Welbeck was forced to leave the match early as injury struck the striker once again.
Mesut Ozil was the player to replace Welbeck, and almost made an instant impact.
The German was inches away from getting his first assist of the season, as he threaded the ball to Iwobi, whose shot went inches wide of Gomes' post.
Ozil's lack of game time however was reflected shortly after as his weak shot one-on-one with Gomes was saved by the keeper, a chance he should've scored.
Watford bite back from the spot
Arsenal's miss was Watford's gain however as the Hornet's were awarded a controversial penalty. Richarlison went down in the box under the challenge of Bellerin.
Replay's showed minimal contact between the two, but that didn't matter, as Troy Deeney tucked away the equaliser from the spot.
After seeing the newly returning Welbeck limp off earlier in the second half, Arsenal's injury luck turned against them once more, as Laurent Koscielny was forced off with what looked to be a recurring achilles injury.
Watford strike late once more this season
Arsenal's luck left the field with Koscielny it seemed, as Watford grabbed yet another late goal this season. In the dying seconds, Tom Cleverley fired Watford ahead from inside the box.
Many questions will be asked of Arsenal, who had a perfect opportunity to make up lost points from teams around them who dropped them earlier today.
Watford now move into the top four following Chelsea's loss to Crystal Palace, moving Arsenal down to 6th place.
An evening to forget for the Gunners, who must react quickly as they travel to Belgrade on Thursday in the Europa League.