Southampton extended their unbeaten run in the Championship to 11 games as Adam Armstrong's two goals helped them outplay Cardiff City at St Mary's.
Saints were 2-0 up after just 15 minutes, with the first goal an exquisite finish from Armstrong after a flowing team move which started in their own penalty area.
His second came via a close-range header and he missed with another golden opportunity to complete his hat-trick.
Che Adams had a goal disallowed for offside and substitute Joe Aribo hit the post as the hosts racked up the chances against a Cardiff side who sank without trace.