Jay Rodriguez scored twice, with Rickie Lambert and Adam Lallana also finding the net, to help Southampton cruise to victory in front of the watching England manager Roy Hodgson at St Mary's on Saturday.
Reserve Newcastle goalkeeper Rob Elliot, in for the injured Tim Krul, produced a string of outstanding saves in the first half, but his efforts proved in vain in a dismal showing from the rest of the Newcastle side.
Alan Pardew started his four-game touchline ban following the end of his three-match stadium suspension for headbutting Hull City's David Meyler earlier this month.
But the Newcastle boss will have been thoroughly disappointed with what he witnessed as Lambert set up Rodriguez for the opener in first-half injury time, before then converting a Lallana delivery shortly after the break to effectively ensure Southampton's victory.
And the win was rounded off as Lallana netted with a stunning long-range strike and Rodriguez coolly powered home his second in the closing stages to cap a wonderful display from Mauricio Pochettino's men.
That stop clearly boosted Elliot's confidence and he again came to the rescue after 15 minutes with an excellent one-on-one save from Lambert.
The hosts' dominance was evident in every facet of the game, with only Elliot, who produced a marvellous stop shortly before the break to again deny Rodriguez, keeping the scores level.
However, Elliot was finally beaten in first-half injury time as Rodrgiuez slotted home a simple finish after Lambert had sprung the visitors' offside trap.
But those alterations had little impact and Southampton doubled their lead just four minutes into the second half when Lambert rattled home Lallana's right-wing cross at the far post.
First, Lallana picked up the ball in midfield, surging forward before unleashing a vicious long-range effort that flew past Elliot into the top corner, before Rodriguez emphatically converted Gaston Ramirez's ball over the top of the Newcastle defence a minute from time.
