Samuel Edozie scored his second goal in as many games to help give Southampton a resounding win over 10-man Blackburn in the first league meeting between the two clubs in 18 years.
Edozie, who scored the crucial equaliser in the Saints' 1-1 draw with Coventry on Wednesday, got the final touch from a corner to put his side ahead just before half-time.
Rovers saw Callum Brittain sent off for a wasteful second booking after kicking the ball away in frustration, and gradually Saints made their advantage pay as Stuart Armstrong doubled the lead just after the hour mark.