Arsenal have missed the chance to move top of the Premier League table after being thrashed 4-0 by Southampton at St Mary's Stadium this evening.
The Gunners were looking to take advantage of Leicester City's earlier defeat at Anfield, but instead fell to a humbling loss at the hands of a Southampton side who went into the match without a win in their last six games in all competitions.
It was the visitors who had the first clear opening of the match when Olivier Giroud's flicked header found Nacho Monreal at the back post, but the left-back couldn't connect with his shot properly, scuffing an effort straight at Maarten Stekelenburg.
There was no problem with the connection at the other end just a minute later, as Southampton broke the deadlock through the unlikeliest of sources and with a contender for goal of the season.
Arsenal failed to adequately clear the ball following a spell of Saints pressure, and it eventually fell to Cuco Martina, who marked his full Premier League debut by curling a strike with the outside of the foot into the bottom corner.
The hosts had a glorious chance to double their advantage right at the end of the first half too when Shane Long was sent clean through on goal, but he got his finish all wrong, lifting the ball over Petr Cech and the crossbar from close range.
Virgil van Dijk had the ball in the back of the net again five minutes after the restart, only to be denied by the linesman's flag, although it would be just five further minutes before Southampton legitimately added a second goal.
It was Long who atoned for his earlier miss, knocking the ball to Sadio Mane before getting into the area for the return pass, leaving him with a simple tap-in past a despairing dive from Cech.
Things got even better for the rejuvenated Saints with just over 20 minutes remaining as James Ward-Prowse swung a vicious corner into a dangerous area that Jose Fonte attacked with more vigour than any Arsenal defender to plant a powerful header home from close range.
Ronald Koeman's side continued to look dangerous against a shaky Arsenal defence, while the Gunners were limited to half-chances at best, including a Mesut Ozil effort that was comfortable for Stekelenburg.
The hosts came within inches of adding a fourth in the dying stages of normal time when Long raced through down the right channel, only to see his effort come back off the foot of the post.
It was only a temporary reprieve for Arsene Wenger's side, though, as Long was handed another chance to add his second of the match, and this time he made no mistake, putting the ball between the legs of Cech having been played in by Dusan Tadic to cap a memorable evening for the Saints.
The result ends a four-match winning streak for Arsenal in all competitions and keeps them second in the table, while Southampton win for the first time since November 7.