Already 2-0 down away to the reigning Premier League champions, any hope that Southampton had of getting something from Sunday's trip to Manchester City all but evaporated as David Silva scored the hosts' third of the game inside 18 minutes.
An own goal from Wesley Hoedt and a Sergio Aguero tap-in already appeared to have put the home side in control inside 11 minutes and their absolute dominance was confirmed before the first half reached the midway point.
Just seven minutes after Aguero's goal it was Silva's turn to get on the scoresheet.
Bernardo Silva slipped in the rampant Raheem Sterling, who has already laid City's second on a plate for Aguero, with the England man clipping a ball into the box from the byline.
Leroy Sane challenged in the air and whilst he was unable to guide it goalwards, the ball dropped perfectly for Silva to volley into the roof of the net first time at the far post.
Alex McCarthy was left a mere spectator in the visiting goal as he was made to pick the ball out of his net for the third time in the encounter, with there still well over an hour of football to be played.