Arsenal moved up to ninth in the Premier League table on Thursday after a goalkeeping error contributed to a 2-0 victory at Southampton.
Meanwhile at Turf Moor, Burnley bounced back from Monday's 5-0 defeat to Manchester City with a 1-0 win against relegation candidates Watford.
Arsenal's first goal came on 20 minutes when Saints goalkeeper Alex McCarthy had his pass intercepted by striker Eddie Nketiah, reports dpa.
McCarthy was outside of his box when Nketiah pounced and skipped past the keeper for an easy tap in.
Joe Willock sealed the victory three minutes from the final whistle with his maiden goal for the Gunners.
Arsenal now have 43 points, six away from European qualification places, after their third away win of the season.
As for Southampton, they equal their own Premier League record of 10 home losses in a season and sit 14th on 37 points.
Burnley are one point behind Arsenal on 11th after their latest win. Jay Rodriguez headed in the winner on 73 minutes after a previous header was disallowed for offside in the first half.
Troy Deeney had his chance for a Watford goal on the hour mark as his header from a corner was stopped by the knee of Dwight McNeil on Burnley's goal line.
Watford's 15th defeat of the season means they still have relegation concerns in 16th place on 28 points, just one clear of the drop zone.