Southampton sealed a shock win over Arsenal at St Mary's on Saturday courtesy of a late Charlie Austin header to seal all three points for new Saints boss Ralph Hasenhuttl.
The home side took the lead as Matt Targett whipped an inviting cross into the area, which Danny Ings duly obliged in thumping home with an emphatic header on the 20th minute.
Arsenal showed good resolve to reply just eight minutes later in similar fashion to the host's opener. Nacho Monreal showed good energy to advance on the left hand side and deliver a well-weighted cross into the Southampton box, with Henrikh Mkhitaryan heading home the equaliser.
Ings repeated the trick with just minutes to go until half time, as the striker rose highest in the Arsenal box to loop a header beyond Bernd Leno from another pinpoint cross from out wide, this time from Nathan Redmond on the right flank to restore Southampton's lead.
Arsenal then received the stroke of luck they needed in the second half, as a hopeful Mkhitaryan strike from outside the box took a cruel deflection off Jannik Vestegaard before trickling past wrong-footed Alex McCarthy to draw the Gunners level once more.
The Gunners piled on the pressure in the later stages, but it was the home side who snatched the late goal as Arsenal were once again undone by a cross, this time from Shane Long, as substitute Charlie Austin met it to slam home the winner.
Key Talking Point
With Nathan Redmond clearly Southampton's primary danger man, using his pace and energy to run at Arsenal's aged back line, much of the interest was in whether the Saints' new boss Hasenhuttl could unlock the English forward's potential in a new system.
The German deployed Redmond in an advanced role, tucked in behind striker Ings, and the forward appeared to feel more comfortable in his freer role in attack. The home side's attack thrived with Redmond providing a central problem for Arsenal's rear-guard to deal with, opening up spaces to attack for others.
Ings found space intelligently, with his movement and initiative setting him on course to score Southampton's opener. Targett's strong run and cross to assist Ings also showcased Southampton's effective use of full backs going forward to test Arsenal in wide areas.
Starting XI: McCarthy (7); Bednarek (5), Yoshida (5), Vestergaard (5); Valery (6), Hojbjerg (7), Romeu (6), Targett (7); Redmond (6), Armstrong (7); Ings (8)
Substitutes: Long (6), Austin (7), Johnson (N/A)
STAR MAN - Danny Ings led by example for the home side as the striker showed a level of energy and desire which set the tone for the Saints from the outset. Ings is not the most physically imposing forward, but he showed good energy to arrive in Arsenal's box at the right time along with a strong desire to win his aerial battles and head his side ahead twice in the match.
WORST PLAYER - Jan Bednarek struggled to keep pace with Arsenal's speedy attackers at times. Pierre-Emerick Aubameyang always fancied his chances of using his pace to get in behind the defender, who was booked for a foul on Alexandre Lacazette.
Key Talking Point
Arsenal went into Sunday's game with a raft of injury problems to deal with in defence, but Unai Emery continued to display strong tactical astuteness to patch up the holes in the Gunners' rear-guard without leaving his side overly exposed.
With Rob Holding out for the season and Sokratis Papastathopoulos and Shkodran Mustafi suspended, Emery shifted Granit Xhaka onto the left hand side of his now-favoured back three, with the fit-again Laurent Koscielny restored at the heart of the trio and Stephan Lichtsteiner operating on the right.
However, Arsenal's vulnerability to high balls and crosses into the box was laid bare with just one recognised central defender at the back, as Ings exploited the Gunners' lack of aerial command in their area with two well-taken headers, before Austin added the finishing touch.
Starting XI: Leno (5); Lichtsteiner (5), Koscielny (6), Xhaka (6); Bellerin (5), Torreira (7), Guendouzi (7), Monreal (6); Mkhitaryan (8), Iwobi (7); Aubameyang (8)
Substitutes: Lacazette (7), Ozil (6), Maitland-Niles (5)
STAR MAN - Pierre-Emerick Aubameyang, like Ings for the home side, gave Arsenal the spark they needed in attack as the Gabon striker put his excellent pace and movement to good use in unsettling the Saints' back line and forcing them onto the back foot.
WORST PLAYER - Though he is naturally suited to the role, Hector Bellerin struggled at right wing back for the visitors. The Spaniard did not have his usual attacking influence down the Gunners' right flank, and struggled with the forward runs of Southampton's left wing back Targett. Bellerin was forced off at half time through injury.
Southampton travel to face Huddersfield at the John Smith's Stadium next weekend before hosting an in-form West Ham side at St. Mary's five days later.
Arsenal, meanwhile, face Tottenham in a second north London derby in the space of a month as the Gunners host Spurs in a Carabao Cup quarter final clash on Wednesday.
Emery's side will enjoy home comforts once more next weekend as Arsenal host Burnley in a Premier League clash at the Emirates on Saturday lunchtime.