Auckland made easy work of the struggling Stags, claiming a 56-8 victory in Invercargill in the Mitre10 Cup.
The visitors romped home in the second half, dominating Southland in all areas of the park.
Auckland scored two first-half tries to lead 14-3 at halftime before running in six more in the second half.
The loss for Southland also meant they broke Northland's record for consecutive losses in the top division of a national provincial championship in rugby, failing to win since October 2016.
The victory moves Auckland back to the top of the table ahead of their final match against North Harbour on Sunday.
Auckland 56 (Mike Sosene Feagai 2, Salesi Rayasi, Fa'atiga Lemalu, Tumua Manu, Caleb Clarke, Desma Liaina, Adrian Choat tries; Harry Plummer 5 con, Dan Kirkpatrick 3 con)
Southland 8 (Joe Walsh try; Tayler Adams pen)