Chelsea put six goals past Southampton without reply to get back to winning ways after back-to-back defeats.
Martin Odegaard, Bukayo Saka and Gabriel Martinelli were on target for Arsenal in their Premier League win over Watford on Sunday.
Arsenal midfielder Martin Odegaard insisted that they had only themselves to blame for, after losing to Everton in the Premier League fixture on Monday.
Demarai Gray scored a stoppage time winner as Everton beat Arsenal 2-1 in the Premier League fixture at Goodison Park on Monday night.
Arsenal have lost all three matches in the new Premier League season and are currently sitting at the bottom of the table.
Both summer signings started on Wednesday as Arsenal eased into the round three of the Carabao Cup with a 6-0 win at West Bromwich Albion.
Arsenal will play West Brom in their opening match of the Carabao Cup this season and Arteta is keen to do well in the competition.
Arsenal Manager Mikel Arteta has been determined to bring in Martin Odegaard entire summer on a permanent basis after his brief loan spell.
Martin Odegaard enjoyed a highly fruitful loan spell with Arsenal in the second half of last season.