Prospective Southampton boss Nathan Jones was in the stands as the Saints beat Sheffield Wednesday on penalties in the Carabao Cup third round.
Luton manager Jones is widely expected to take charge at St Mary's imminently.
He saw Josh Windass give League One Wednesday the lead, before James Ward-Prowse equalised from the penalty spot just before the break.
With no further goals, penalties were needed - and Dominic Iorfa's saved spot-kick meant the Saints progressed.