Graziano Pelle marked his Southampton debut with two goals as Ronald Koeman's men eased past Belgian minnows Sporting Hasselt.
The Italian striker opened the scoring in the fifth minute and added his second just past the half-hour as the Saints eased to a 6-0 victory.
Second half goals from Sam McQueen, Emmanuel Mayuka, Sam Gallagher and an own goal completed the scoring against the Belgian third division side.
Joe Cole made his debut for Aston Villa as Paul Lambert's side edged a 3-1 win over Mansfield at the One Call Stadium.
Cole, a summer free transfer from West Ham, played the whole first half in which the Sky Bet League Two side led through an Alex Fisher header.
Darren Bent made the difference in an entirely changed second half line-up, tapping home an Alan Hutton cut-back to equalise on 61 minutes.
Gary Gardner put Villa in front in the 85th minute and Bent scored his second when he headed home an Andreas Weimann cross in the final minute.