With Manchester City vying for a place in the FA Cup final this weekend, Arsenal had the chance to move seven points clear of their title rivals at the summit when they kicked off the weekend's action.
Victory for the table-toppers over the 20th-placed Saints would have also sealed a top-four finish and a return to the Champions League for the first time since 2016-17 for Arsenal, but they got off to a disastrous start.
Ruben Selles's side stormed into a 2-0 lead inside 14 minutes to silence the Emirates crowd, and the Saints were leading 3-1 approaching the final five minutes of an astounding contest.
However, Arsenal produced one of their habitual late comebacks to steal a point in a six-goal thriller, but both sets of players and fans were visibly deflated at the final whistle, with a draw hardly helping the Gunners' title bid or Southampton's fight against the drop.
Speaking to the media after another frenetic battle, Arteta lamented the manner in which his side conceded their three goals but was overjoyed with their late response in North London.
"Well at the end, empty obviously, because it was a very emotional game and I'm disappointed because we didn't get the three points," arsenal.com quotes Arteta as saying in his post-game press conference.
"After all that happened in the game I still believe that we deserved it, but we have to look in the mirror because we gave three really easy goals away and when you do that it's extremely difficult to win in this league.
"The response of the players, I cannot love them more, honestly. It is a joy to coach them and it is a joy to be a part of this club and to experience what I have experienced with this team. At the end the magic moment was there to be taken, we had two big chances at 3-3 to score but today it didn't happen unfortunately."
A horror mistake from Aaron Ramsdale gifted Carlos Alcaraz the opening goal on a plate with just 27 seconds gone, and the Argentine then turned provider for Theo Walcott to double the visitors' lead at his old home.
Gabriel Martinelli pulled one back for Arsenal with a sweetly-struck volley not long after, but the Saints shut up shop early in the second half and restored their two-goal cushion through Duje Caleta-Car's header.
However, as they have done numerous times during a frenzied campaign, Arsenal refused to wave the white flag and incredibly turned the game on its head through Martin Odegaard and Bukayo Saka's efforts in the dying embers.
Substitute Leandro Trossard also hit the crossbar in added time, but Arsenal ended the game as the first table-topping team to concede three goals to the side starting the day at the foot of the table, and Arteta has warned his players that Man City will need no second invitation to expose their defensive frailties.
"At the end it's tough because you can see them on the floor and you have to leave them. I think everybody has to disconnect tonight, digest it and tomorrow start to think what is the best way to go to Manchester to beat them," Arteta added.
"The confidence is there, it's those moments that we need to cut back. At this level, we cannot give away the goals that we have given. It's as simple as that."
Arsenal's lead over Man City now stands at five points, but the champions have two games in hand and will welcome Arteta's side to the Etihad next Wednesday in a tantalising top-of-the-table battle.