Olivier Giroud's last-gasp header salvaged a point for Arsenal in a 1-1 draw at Southampton on Sunday as Arsene Wenger's side avoided a second successive Premier League defeat.
Wenger's team appeared destined to follow last weekend's home loss to Manchester United with another setback when they trailed to Charlie Austin's third minute goal.
But France striker Giroud conjured a response with two minutes left when he directed Alexis Sanchez's cross past Fraser Forster shortly after appearing as a substitute.
A single point, though, denied Arsenal the chance to climb into the top four.
Southampton can consider themselves unfortunate to have seen Austin's fourth goal in three starts cancelled out late on, but Mauricio Pellegrino's side have won just one of their last seven games.
After seeing his side ship two early goals in the United defeat, Wenger had demanded concentration from the start
Unfortunately for Wenger, it appears his words went unheeded.
Per Mertesacker had been restored to the line-up in place of the injured Shkodran Mustafi.
But the Germany international was left red-faced just two minutes into his return as he gifted Southampton the goal that allowed Pellegrino's side to control the first half.
A poor clearance from Mertesacker conceded possession deep inside his own half and then slipped as he attempted to make up for his mistake, allowing Dusan Tadic the time and space to pick out Austin's run into the box where the striker finished from 12 yards out.
It was the perfect start for the home side and they should have been two up inside five minutes when Tadic and Austin again combined to open up the unconvincing Gunners backline.
This time Tadic delivered a through ball from near the halfway line, sending Austin into space with a clear run on goal, but the forward placed his shot too close to keeper Petr Cech who was given the chance to save.
- Vulnerable -
Arsenal looked vulnerable to every early Southampton attack and the satisfaction that followed Thursday's 6-0 Europa League defeat of BATE Borisov was quickly forgotten.
Theo Walcott and Jack Wilshere had both impressed in that win but Wenger adjudged that neither had done enough to force their way into his starting line-up.
Wilshere in particular had cause to feel hard done to with Granit Xhaka making little impression in the central midfield areas as Arsenal fought to get back on level terms.
In fact most of the visitors' first half opportunities came on the break, and in particular when Alexis Sanchez controlled a Southampton corner inside his own area and led a sweeping attacking move that was halted by Pierre-Emille Hojbjerg's saving tackle as Alexandre Lacazette made to shoot.
And when Aaron Ramsey did manage to fire off a shot towards Forster's goal – a first time effort from Sanchez's 32nd minute cross – the Southampton keeper reacted superbly to dive low to his left after push the ball beyond the post.
Arsenal pressed forward with more purpose after the restart, dominating possession yet unable to penetrate a home defence that demonstrate far more resilience than their own.
But their attempts to force an equaliser left them exposed at the back.
Oriel Romeu almost found a way past Cech when his 20-yard drive struck the bar before a routine ball over the Arsenal defence led to Tadic setting up another good opportunity, this time for Ryan Bertrand.
Arsenal looked to have run out of ideas until Giroud found space between the Saints defenders and headed home from Sanchez's cross.