TOWN'S hopes of a first Division II double of the season were dashed at The Dell.
Eddie Boot's in-form side, who had taken five points from the last six, started brightly at Southampton, who had been beaten 1-0 at Leeds Road in the third game of the season.
Kevin McHale gave them a fifth-minute lead they looked more than capable of building on.
But inexplicably, the visitors lost their way late on in the first half and ended up slumping 3-1 to their mid-table rivals.
Brian Clifton (2) and Tommy Mulgrew grabbed the goals to cheer home fans in an 11,262 crowd.
It had been a bad week for Saints, with their star England Under 23 winger Terry Paine asking to go on the transfer list.
Manager Ted Bates nonetheless included him against Town, and his flank contest with England international left-back Ray Wilson was an interesting one.
Saints had other talented players in defender Tony Knapp, who was said to be on the verge of an England call-up, and inside-forward George O'Brien, the former Leeds player who was their top scorer with 18 goals.
But it was all Town in the early stages, and by the time McHale netted with a precise header from Mike O'Grady's cross, the supplier of the goal had already sent a sizzling 20-yard shot just over.
Town were stronger in the tackle and cleaner with their passes, and O'Grady again tested keeper Tony Godfrey with a stinging 10-yard drive.
Little had been seen of the home attack until Clifton levelled against the run of play with a long-range shot after 36 minutes.
Town suddenly looked shaky, and O'Brien almost put Saints ahead a minute before half-time when his 15-yard shot beat keeper Harry Fearnley but struck a post and bounced back into play.
Republic of Ireland defender Pat Saward played a crucial marshalling role as the home side pushed forward on the resumption.
The pressure told after 70 minutes when Clifton counted with another well-placed shot.
Mulgrew clinched the points for Saints with a close-range finish after 80 minutes.
Town's Chris Balderstone and West Brom's Brian MacReady were the players to catch the eye in a 0-0 Central League draw at Leeds Road.
And Town Juniors right-back Maurice Tillotson was selected for an England Youths trial to take place at Peterborough.
Inside-forward Tony France, meanwhile, was on his way to Fourth Division Darlington for an undisclosed fee agreed with Feethams manager Eddie Carr, a former Town player.
The Sheffield-born player had made nine Town appearances, scoring twice, only for his progress to be slowed by National Service.