The Gunners boss was given public backing by the club’s hierarchy during the international break but he was reliant on a Lacazette brace to twice bring his side from behind to earn a 2-2 draw.
The south-coast side have not won a league game at Arsenal since 1987 but looked on course to end that run as James Ward-Prowse tapped home after having a penalty saved by Leno, cancelling out Lacazette’s first following Danny Ings’ opener for the visitors.
Arsenal are now winless in six games across all competitions and have celebrated victory in just two of their last 11 Premier League games.
For Ralph Hasenhuttl’s side, this would have been a much-needed morale boost but they have not won in the league since September 14.
While bitter rivals Tottenham celebrated victory at West Ham earlier in the day having opted to sack Mauricio Pochettino and replace him with Jose Mourinho, Arsenal put in another mediocre display.
The club may have stuck by Emery but the jeers which greeted the full-time whistle suggests the majority of supporters may soon be calling for a change.
Southampton had a great early chance as Stuart Armstrong robbed former Celtic team-mate Kieran Tierney of possession with a little over 30 seconds gone but he could only shot wide.
The lead would belong to the visitors nine minutes later as they caught the Arsenal defence napping.
Nathan Redmond was fouled by Calum Chambers and the recalled Ryan Bertrand played a quick free-kick into Ings, who ran in on Leno’s goal and converted the opener off the inside of the post.
Lacazette would equalise as Pierre-Emerick Aubameyang’s shot was blocked into the path of his strike partner, who made no mistake in turning home his first goal since September 1.
The rest of the half was a scrappy affair, Southampton already happy to start running down the clock while Arsenal still proved wasteful in possession as a smattering of jeers from the home fans greeted the half-time whistle.
Emery responded by reverting to a back four and introducing club-record signing Nicolas Pepe in place of Chambers.
Saints goalkeeper Alex McCarthy was called into action soon after the restart to keep out Aubameyang after the ball had broken fortuitously into the path of the Arsenal skipper.
Pepe then summed up his start to life in England as he was slipped through behind the Southampton defence and ran in one-on-one against McCarthy before attempting to square to a team-mate instead of take on the strike.
The Ivory Coast forward did well to make contact with Tierney’s cross but his scissor kick came back off the woodwork.
Emery’s side started to control proceedings but were lucky not to fall behind a second time as Sokratis Papastathopoulos dallied and lost the ball to Cedric Soares inside his own penalty area.
The Portugal full-back’s cross evaded Michael Obafemi, the young forward six yards out from an open goal but unable to make contact.
Another error would see Southampton take the lead with 20 minutes remaining as Tierney pulled back on Ings following a ball back into the box, with referee Stuart Atwell pointing to the spot.
Ward-Prowse stepped up but saw his low penalty kept out by Leno, only to tuck away the rebound and celebrate in front of the travelling support.
Emery turned to youngsters Gabriel Martinelli and Joe Willock and it was the latter who had a header well-saved by McCarthy.
The England Under-21 international was then heavily involved at the other end as he raced back to clear Moussa Djenepo’s goalbound shot off the line.
A number of stoppages led to seven minutes of injury-time as Djenpo spurned a fine chance to seal the points and it proved to be costly as Lacazette thrashed home at the back-post to salvage a point which does little for Emery’s current standing.
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