Neal Maupay told Arsenal to be more humble as the Brighton striker was the Gunners' villain with a 95th minute winner to secure a 2-1 victory on Saturday.
The visitors were unhappy with Maupay's part in the challenge that saw goalkeeper Bernd Leno stretchered off in the first half.
The Gunners still looked on course for the three points when Nicolas Pepe opened the scoring with a stunning strike 22 minutes from time.
But the defensive deficiencies that have haunted Arsenal's season under three different managers have not been ironed out during a three-month layoff as Lewis Dunk bundled home an equaliser before Maupay snatched Brighton's first league win of 2020 late on.
"Some of the Arsenal players need to learn humility sometimes," said Maupay. "They were talking a lot first half, the second half when they were 1-0 up, and they got what they deserved."
Maupay and Matteo Guendouzi had to be separated at full-time as tempers flared.
Another crazy ending!
Arsenal players confront match-winner Neal Maupay, whose earlier challenge forced Bernd Leno off injured...
— The Premier League is BACK on BT Sport (@btsportfootball) June 20, 2020
However, the Frenchman denied any responsibility for the injury that saw Leno twist his knee after a slight nudge from Maupay.
"At half-time I went to Mikel Arteta to apologise. I never meant to injure their keeper," added Maupay.
"I have been through a bad injury, so I know it is hard, but I never meant to hurt him."
A second defeat in four days leaves Areta's side still eight points outside the top four in ninth, having played a game more than fourth-placed Chelsea.
And Spaniard Arteta labelled the manner of the defeat "unacceptable" from a commanding position 15 minutes from time.
"It's a very difficult one to take because it is unacceptable the way we lost the game," said the Spaniard.
"We missed so many chances, the fact that we gave them the first goal and we did not compete for the second goal."