Arsenal s Gabriel Magalhaes, center, scores the third goal during the English Premier League soccer match between Arsenal and Southampton at Emirates stadium in London, Saturday, Dec. 11, 2021. AP
Arsenal was without captain Pierre-Emerick Aubameyang, who was dropped from the squad for disciplinary reasons, but Alexandre Lacazette started in his place and netted the opener in the 21st minute.
The French striker finished off a flowing move that started with goalkeeper Aaron Ramsdale playing the ball out of the back and ended with Bukayo Saka crossing for Lacazette to sweep into the net for his first goal since mid-October.
That goal came against the run of play after a strong start by Southampton, but Odegaard doubled the lead just six minutes later by heading home a cross.
Southampton looked vulnerable on counters after that and Arsenal added the third in the 62nd when defender Gabriel headed home Gabriel Martinelli's corner _ just three minutes after the center back had a scrambled effort ruled out for offside.
Martinelli and Saka then both hit the woodwork as Arsenal threatened to overwhelm the visitors.
Arsenal manager Mikel Arteta said before kickoff that Aubameyang _ who has been going through a stretch of poor form and was dropped to the bench for the Gunners' previous game _ had been left out because of a ``disciplinary breach.`` However, Arteta refused to provide any further details after the game.
The win put Arsenal just one point behind fourth-placed West Ham, which visits Burnley on Sunday.
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