Northants made the Twenty20 Cup last eight with a predictably comfortable 20-run win over Mids/West/Wales Division also-rans Glamorgan.
Riki Wessels hit an unbeaten 66 as Northants totalled 157-7, backed by Nicky Boje's 23.
Boje then took 3-14 as Glamorgan slumped to another disappointing 137-9.
Northants now need to win at home to Worcestershire on Sunday to earn a home quarter-final, while Glamorgan go to Bristol keen to avoid the wooden spoon.
Only a comprehensive victory over Gloucestershire will prevent the 2004 semi-finalists from finishing bottom of the group.
Northants are through to the last eight for the fifth straight year - but they are yet to go any further.
Somerset and third-placed Warwickshire have also qualified for the quarter-finals. As to who gets home advantage, that will not be decided until Sunday.