Southampton manager Ralph Hasenhuttl apologised to Arsenal counterpart Unai Emery after forgetting to shake hands amid the emotion of a late victory on his home debut.
The Saints ended Arsenal’s 22-match unbeaten run thanks to Charlie Austin’s 85th-minute header with Hasenhuttl running on to the pitch to celebrate with his players on the final whistle.
“I had to run to my guys because they were waiting. I shook hands later and it was OK,” said Hasenhuttl.
“It’s what I wanted to feel when I came to the Premier League, this atmosphere after the game, and to celebrate such a moment is something very special for me.”
In a see-sawing encounter, the hosts took the lead after 20 minutes as Danny Ings muscled home a header from Matt Targett’s cross.
Henrikh Mkhitaryan nodded in shortly after for Arsenal, following good work by Alex Iwobi and Nacho Monreal – but Ings struck again just before the break.
Nathan Redmond’s floated cross was precise and Ings cushioned a looping effort into the far corner.
Arsenal turned the screw in the second half and restored parity as Mkhitaryan’s shot deflected in off Jannik Vestergaard.
The Gunners had their chances with Alex McCarthy impressing in the home goal, but Southampton were dangerous on the break and Shane Long had a goal rightly ruled offside before providing a teasing cross for Austin’s winner.
The victory takes Southampton out of the relegation zone and up to 17th.
At the final whistle, Austrian Hasenhuttl – nicknamed the ‘Klopp of the Alps’ during his spell at previous club RB Leipzig – joined his players’ on-pitch huddle before whipping up more decibels from the home support.
With rivals Chelsea winning away at Brighton, Arsenal are now three points adrift of the top four.
Earlier in the week, Hasenhuttl had sent free drinks vouchers to Southampton’s season ticket-holders to mark his first game at St Mary’s. His accompanying letter promised an “intensive and very hard-working” environment and his players responded by trumping Arsenal’s quality with industry and tenacity.
Ings, whose last headed Premier League goal was for Liverpool in Brendan Rodgers’ final match in charge back in October 2015, looked a potent aerial threat, finding space in between Arsenal’s three-man defence to score his two goals.
Also heartening for a team at the wrong end of the table, the Saints defence was galvanised.
Jan Bednarek typified their whole-hearted commitment, sliding in to steal the ball as Pierre Emerick Aubameyang was poised to put Arsenal ahead in the first half.
Hasenhuttl lived every moment on the touchline, visibly reminding himself to stay off the pitch as he celebrated Ings’ first, before ultimately giving way to his emotion at the final whistle.
“I heard when it works like this you have to do it every game at home,” he said afterwards of his free drinks for the home fans. “We’ll have a look.”
For all the improvements made by Arsenal under Unai Emery, they have an unwelcome habit of making sluggish starts.
They are yet to lead at half-time in a Premier League match this season and finally, against a revved-up Southampton, they found they had left themselves with too much to do.
Emery’s initial solution to his defensive shortages may not have helped.
With Rob Holding and Konstantinos Mavropanos injured and Sokratis Papastathopoulos and Shkodran Mustafi suspended, Emery opted for a makeshift back three of the recently-returned Laurent Koscielny, midfield specialist Granit Xhaka and 34-year-old Stephan Lichtsteiner.
An enforced change of tactics – with the injured Hector Bellerin replaced by Alexandre Lacazette as the Gunners reverted to a back four – gave them them more impetus after the interval.
Arsenal immediately looked more dangerous with Aubameyang’s goal-bound shot cleared by Vestergaard before Lacazette picked the pocket of Oriel Romeu to set up Mkhitaryan’s shooting position for the second.
They forced Southampton deep, but not beyond breaking point, and, when goalkeeper Bernd Leno misjudged Long’s teasing cross, their unbeaten run – which had stretched back to August – was over.