Brighton took the lead at the Emirates Stadium when Leandro Trossard turned home a low cross from Enock Mwepu to finish a good move from the visitors.
Arsenal had struggled to create chances but thought they had levelled through a close-range effort from Gabriel Martinelli, only for a lengthy VAR check to cancel out his header.
Brighton doubled their lead through Mwepu’s low drive from the edge of the box following a neat interchange between Trossard and Moises Caicedo.
Dawson said: “He has been brilliant for the whole match and easily the best player on the pitch. His work rate and composure on the ball has been unbelievable.
“Trossard and Caicedo linked well and his cross came across and Mwepu’s finish was excellent. The technique and skill to side-foot beyond Ramsdale on the half volley was something else.
“A really good goal, it’s a long way back for Arsenal and well deserved.”
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