Southampton ended Arsenal's 22-match unbeaten run on Sunday as Charlie Austin came off the bench to head Ralph Hasenhuttl to his first victory as Saints manager with a surprise 3-2 win for the hosts at St. Mary's Stadium. 

Danny Ings surprised a porous Gunners backline with two headers before the break to put them in a 2-1 lead, as Henrikh Mkhitaryan recorded with a header of his own before his deflected effort rolled in after 53 minutes to level.

Austin came on in Ings' place and made the most of Bernd Leno's decision to come for the ball with only five minutes left, heading past the German for a deserved three points. 

Hasenhuttl's first win as Southampton manager lifts Saints outside the relegation zone and up to 17th, while Arsenal remain fifth following their first defeat in all competitions since August.

Laurent Koscielny Return Can't Cover Frail Arsenal Defence

Arsenal fans would have been overjoyed to see club captain Laurent Koscielny return to their Premier League lineup for the first time since April, when he suffered the Achilles injury that's kept him sidelined since.

It was much needed considering defenders Sokratis Papastathopoulos, Shkodran Mustafi and Rob Holding are all either injured or suspended, although it wasn't the defensive performance—individually or as a team—that fans sought.

Unfair as it may be to criticise a defender after seven months injured, it was on the key occasions that Koscielny's lack of match preparedness showed. For example, his decision to try clearing Matt Targett's curling cross for Ings' first goal with his foot—rather than his head—drew confusion:

He completely lost Ings' run for the Southampton striker's second, although Stephan Lichtsteiner also had some responsibility in failing to pick up the run:

Granit Xhaka also had some culpability in what was a forgettable defensive display from the visitors. Xhaka was started by manager Unai Emery on the left of a back three, with Nacho Monreal ahead. It may have been better to swap those two or give youngster Ainsley Maitland-Niles a chance in Xhaka's place. 

Injured full-back Hector Bellerin was hooked in place of Alexandre Lacazette at half-time, with Koscielny and Xhaka left to form the centre-back partnership in a back four. Arsenal blogger YankeeGunner wasn't a fan of the tactic:

Statistician Orbinho explained how Emery's attack has thus far been able to make up for the lack of structure at the back, although key absences clearly took their toll at St. Mary's:

Leno made the choice to come and claim Shane Long's floated cross in for Austin's late intervention, but there was again a sense of indecision among the defenders, who failed to deal with the Englishman's run.

Recruitments were made in the summer to bolster Arsenal's options, but even with Koscielny back fit, it's clear that's where further investment is needed for the Gunners.

Danny Ings Will Prove a Saints Bargain at £20 Million

Although Ings is officially on loan at St. Mary's this season, it was reported at the time of his transfer that the deal—an initial £18 million with £2 million in add-ons—would go through permanently in July 2019.

It's an agreement that will prove hugely valuable to the Saints, who now have a capable tactician in Hasenhuttl, one able to get the best out of a clearly frustrated talent in Ings.

The 26-year-old now has six goals this season, and while Arsenal's defence has encountered criticism, there's a lot to be said for his mentality in standing up to one of the Premier League's elite.

Not only that, but the double helping will have undoubtedly reminded the striker of just how lethal he can be against big opposition, a key confidence boost for any striker, per Squawka:

In the inflated transfer market of today, finding reliable goalscorers for a modest fee is increasingly difficult. Not only that, but Ings is a homegrown asset who's only likely to appreciate.

Hasenhuttl demonstrated his own class by withdrawing one English scorer for another and eventual match-winner Austin, but it was Ings' performance that stood out for the home side:

After four matches out with an injury, Ings could hardly have asked for a better return to the side than by bringing his record up to three goals in his last three league games.

Saints have shown signs of improvement under Hasenhuttl, but Sunday saw them turn promise into points, with Ings primed to get over his Anfield disappointment and blossom under the new regime.

What's Next?

Arsenal won the first north London derby of the season earlier in December and will face Tottenham Hotspur again in the Carabao Cup quarter-finals on Wednesday. Southampton aren't back in action until Saturday, when they travel to Huddersfield Town in the Premier League.