Southampton striker Brett Ormerod scored twice as the Saints notched up their second league win of the season to condemn struggling City to their fifth defeat in nine games.
Ormerod scored his first ever top-flight double at either end of the first half to fire Southampton to their second win in four days following Wednesday's 6-1 Worthington Cup win over Nationwide Division Two side Tranmere.
The 25-year-old opening the scoring just after 64 seconds with his first league goal of the season.
Ormerod headed home from close range after England international defender Wayne Bridge had delivered the perfect cross from the left.
Newly-promoted City had goalkeeper Peter Schmeichel to thank for keeping them in the game with a string of fine saves in the minutes after Ormerod's opener.
The former Manchester United and Aston Villa star needed to be at his brilliant best to keep out Southampton midfielder Fabrice Fernandes' long-range shot with a fantastic one-handed save in the 13th minute.
And Saints found Schmeichel difficult to beat six minutes later when the ex-Danish international brilliantly tipped left-back Bridge's 25-yard shot past the post.
Ormerod thought he had made it 2-0 in the 25th minute only to be denied by an unbelievable close-range stop from Schmeichel after Bridge had played him in.
But the former Blackpool striker was not to be denied and completed his double three minutes before half-time to make it 2-0.
Ormerod extended Southampton's lead from close-range after the in-form Schmeichel had spilled the striker's first-time shot after Bridge had again crossed from the left.
Southampton's victory was soured somewhat with the sending off of substitute Marian Pahars six minutes from time.
The Latvian international, who had replaced the injured Ormerod early in the second half, was dismissed after picking up his second booking of the afternoon for diving