The north London side, who headed into the game on the back of their impressive 2-1 win over Manchester City last week, failed to click into gear at St Mary’s and fell behind in the 19th minute when Cuco Martina’s curling effort beat Petr Cech.
Shane Long doubled the home side’s lead in the 55th minute when he tapped home from close range, before Jose Fonte made it 3-0 when he headed in from a corner in the 69th minute.
Long then added gloss to the scoreline when he finished through Cech’s legs.
The result left Arsenal second in the Premier League table and two points behind leaders Leicester City, who were beaten 1-0 at Liverpool earlier in the day.
Southampton’s thumping win inevitably prompted plenty of activity on Twitter – and here are some of our favourite updates.
What a shift Shane Long puts in for his team #Workrate
— Darren Huckerby (@hucks6dh6) December 26, 2015
Poor performance tonight Had a good Christmas up till now
— Ray Parlour (@RealRomfordPele) December 26, 2015
— Mario Melchiot (@MarioMelchiot) December 26, 2015
Oh my goodness @ShaneLong7
— Matt Le Tissier (@mattletiss7) December 26, 2015
Piersy this is just a bad day at the office. Take your teeth out, have a cup of Horlicks and go to sleep @piersmorgan
— Lord Sugar (@Lord_Sugar) December 26, 2015
Shameful bunch of chokers. I'm going to bed. #afc
— Piers Morgan (@piersmorgan) December 26, 2015
Tres complique pour Arsene Wenger. Beaucoup de questions a se poser!!.
— David Ginola (@teamginola) December 26, 2015
Arsenal as pathetic as usual
— James Hurst (@hursty43) December 26, 2015
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