A sensational goal from Cuco Martina, two second half strikes from Shane Long and a José Fonte header earned Saints a stunning 4-0 win over the Gunners at St Mary’s.
The hosts were without a win from their previous five Premier League games, but they put an end to that run with a fine victory that owed to the hard work and composure of Ronald Koeman’s side.
They led 1-0 at half-time thanks to a wonder-strike from Cuco Martina on the defender’s first Premier League start. The full-back connected with a volley using the outside of his boot from fully 30 yards out which arched into the far corner of the net.
Saints had two goals ruled out in between their next strike, with Long and Van Dijk each seeing efforts not given for a foul and an offside decision respectively.
It was 2-0 ten minutes into the second half when a patient move ended with Long finishing well from Mané’s assist.
Fonte wrapped up the victory with a brilliant near post header from Ryan Bertrand’s corner before Long rolled home the game’s fourth with almost the last kick of the match to extend Arsenal’s winless run at St Mary’s to five games.
Goalkeeper Maarten Stekelenburg recovered from a toe injury to return to the starting line-up as one of four changes made to the team.
Another of those coming into the team was Cuco Martina, who came in at right back.
All players wore black armbands as a mark of respect to former Arsenal and England manager Don Howe who passed away late last week.
Visitors Arsenal got the game under way, attacking the Chapel stand, which they made an early venture towards with the club’s top marksman Olivier Giroud headed a corner over from close range.
The Gunners went close again on 17 minutes when left back Nacho Monreal popped up on the end of a loose clearance inside the Saints area, before he struck a cross which deflected off Martina and into the grateful arms of Stekelenburg.
Then, out of the blue, two minutes later Saints opened the scoring in terrific style.
Arsenal skipper Per Mertesacker cleared the ball into space outside of the visitors’ area, where Cuco Martina without hesitation, struck a first time volley with the outside of his boot which curled past Petr Čech and into the side of the net for 1-0.
The goal lifted the roof off St Mary’s as the hosts ended a run of two games without scoring thanks to a strike that will live long in the memory for the Curaçao full-back.
Saints sensed a chance to double their lead, with Ward-Prowse taking his time before cutting in to shoot wide. The same man also curled a shot over after Ryan Bertrand cut the ball back to the midfielder on the edge of the area.
Just past the half hour, Shane Long was perhaps harshly penalised for foul on Mertesacker who he robbed of the ball, before audaciously nutmegging Čech from six yards out. The goal was ruled out for a foul, while the Irishman was also subsequently booked for kicking the ball away ahead of play restarting.
Long ended the half with another good chance when Mané released him into the area, but after a good first touch, the striker couldn’t keep his shot down.
Just before that, Özil offered a reminder of Arsenal’s threat by heading wide at the near post, but Saints held their gone goal advantage in place heading into the break.
Saints continued to impose themselves on the Gunners after the restart, and had the ball in the net on 50 minutes when a Ward-Prowse free-kick was headed in by Virgil van Dijk. However, the flag went up for offside as the ball crossed the line.
Keeper Petr Čech then stayed down with a knock to the head he sustained in going for the ball, but was deemed fit to carry on.
Five minutes later he was picking the ball out of his net as the hosts found a legitimate second goal thanks to Shane Long. The move started from deep inside the Gunners half where Steven Davis played the ball into Long, who turned it out to Mané and the Senegalese served it back on a plate for the Irishman to roll home for 2-0 from eight yards out.
Not long past the hour mark Jordy Clasie went off with what appeared to be a minor knock, but Saints were unaffected as they made it 3-0 on 69 minutes.
A delicious in-swinging corner from Ryan Bertrand was emphatically headed home at the near post by José Fonte for the defender’s 15th goal of his Saints career, and the goal that sealed all three points for the hosts.
Substitute Dušan Tadić warmed the hands of Čech from distance with a fierce strike, while Long also hit the base of the post as Saints could have easily extended their lead before they eventually did.
It came with almost the last kick of the game, as Long received the ball from Tadić and rolled the ball under Čech for the game's fourth goal.
At the other end, Mesut Özil saw a cross bobble across the goal line as fortune also favoured Saints to their first clean sheet in six league matches to go with the welcome three points.
Southampton team (4-2-3-1): Maarten Stekelenburg; Cuco Martina, José Fonte (c), Virgil van Dijk, Ryan Bertrand; Victor Wanyama, Jordy Clasie (Oriol Romeu 67); James Ward-Prowse (Dušan Tadić 71), Steven Davis, Sadio Mané (Juanmi 81); Shane Long. Unused substitutes: Paulo Gazzaniga (GK), Maya Yoshida , Gastón Ramírez, Steven Caulker
Booked: Long (34)
Goals: Cuco Martina (19), Long (55) & (90), Fonte (69)
Arsenal team (4-2-3-1): Petr Čech; Héctor Bellerín, Per Mertesacker (c), Laurent Koscielny, Nacho Monreal; Aaron Ramsey, Mathieu Flamini (Calum Chambers 73); Mesut Özil, Theo Walcott (Alex Iwobi 78), Joel Campbell (Alex Oxlade-Chamberlain 64); Olivier Giroud. Unused substitutes: David Ospina (GK), Kieran Gibbs, Gabriel Paulista, Jeff Reine-Adelaide
Referee: Jonathan Moss
Attendance: 31,669 (including 3,217 away)