Arsenal were left stunned, as they fell to a 2-1 defeat at home to Watford on Tuesday evening in the Premier League.
The visitors broke the deadlock in the 10th minute when defender, Younes Kaboul powered home a free-kick from 25-yards out. Troy Deeney doubled Watford’s advantage three minutes later as he tapped home from close range, after goalkeeper Petr Cech saved an initial effort from Ettiene Capoue.
Things turned from bad to worse for Arsenal as midfielder Aaron Ramsey was forced off with injury, and the Welshman was replaced by Alex-Oxlade Chamberlain. The hosts failed to register a single shot on target and the score remained 2-0.
Arsenal started the second half brightly, as Arsene Wenger opted to put in Theo Walcott for Oliver Giroud. The hosts left no stone unturned and attacked Watford’s goal with real intent from the start of the second half.
Soon the relentless pressure by the Gunners paid off. They pulled one back in the 59th minute as Alex Iwobi calmly turned home Alexis Sanchez's cross at the far post.
Watford responded with a double change after 70 minutes as on-loan striker from AC Milan M'Baye Niang and Doucoure replaced Isaac Success and Valon Behrami. Despite the changes, Walter Mazzari’s men stayed on the back-foot and opted to defend and soak up Arsenal’s pressure.
Arsenal came close to equalize on 84 minutes, but Lucas Perez's stinging effort from close range crashed against the crossbar.
However, Watford managed to see off a late surge from Arsenal to claim a famous victory—their first top-flight victory over the Gunners since 1988.
Arsenal are nine points behind league leaders Chelsea, who held Liverpool to a 1-1 draw at Anfield.
Liverpool goalkeeper Simon Mignolet was caught off guard from a superb David Luiz free kick midway through the first half, which gave Chelsea the lead in the first-half.
Georginio Wijnaldum's close-range header levelled the scores in the 57th minute as Liverpool avoided a fourth consecutive home defeat in all competitions.
But Mignolet proved to be the hero at Anfield as he made amends for his mistake by denying Diego Costa from the penalty-spot, after Joel Matip had tripped the Spanish striker 14 minutes from time.
Third-bottom Crystal Palace won in the league for the first time under new manager Sam Allardyce as Scott Dann and Christian Benteke scored the goals in a 2-0 victory at Bournemouth.
Tottenham Hotspur missed the chance to close the gap on Chelsea after they were held to a frustrating 0-0 draw by Sunderland on Tuesday evening.
Despite dropping points, Spurs have moved up to second spot, after Arsenal were beaten by Watford.
Middlesbrough snatched a point in a 1-1 draw at home to West Bromwich Albion but remain in trouble.
James Morrison's early strike was cancelled by Alvaro Negredo’s penalty as both teams shared spoils at the Riverside stadium.
Swansea City moved out of the relegation zone, after securing a 2-1 win over Southampton at the Liberty Stadium.
Alfie Mawson opened the scoring for the hosts after 38 minutes, before Shane Long leveled things in the 57th minute. However, Gylfi Sigurdsson's 70th minute effort earned Swansea a second consecutive win in the Premier League.
Elsewhere, champions Leicester City's struggles continued, as they suffered a 1-0 defeat to Burnley at Turf Moor; courtesy Sam Vokes’s close range strike in the 87th minute.