Glamorgan 254 (Khawaja 103, Sanderson 3-30) and 121 for 4 require a further 313 runs to beat Northamptonshire 281 and 406 for 9 dec (Duckett 133, Vasconcelos 79, Crook 73, Procter 70)
Northants are well placed to win their second consecutive championship game and move off the bottom of the table after outplaying Glamorgan on the third day at Sophia Gardens.
After the visitors had declared on 403 for 9, the home team were set the mammoth total of 434 to win. They closed on 121 for 4, and with Usman Khawaja already out, their chances of avoiding defeat are slim on a pitch where the odd ball is misbehaving for the seamers, and there was sufficient turn for Seekuge Prasanna to take two late wickets.
When play resumed on another glorious morning, Ben Duckett and Luke Procter extended their opening partnership to 208, and surpass the previous record for that wicket against Glamorgan, established by Brian Reynolds and Mickey Norman at Northampton in 1962.
Procter, who made an assured 70, was the first to go, when his inside edge off van Der Gugten was well caught by Cooke, and three overs later Duckett's season best of 133 from154 balls which included 22 fours, ended when he mishit a short ball from Rory Smith to midwicket.
The third wicket then fell for the addition then fell for only seven runs, when Alex Wakely sliced a drive to second slip, and the Glamorgan bowlers' efforts were rewarded further when Richard Levi and Adam Rossington perished in quick succession.
Any hopes Glamorgan might have had of a further collapse were dashed by Ricardo Vasconelos and Steven Crook who extended Northants' lead to over 300, and shared a partnership of147 for the sixth wicket.
Vascolenos, a 19yr old South African left hander, who qualifies by owning a Portuguese passport, again made an impression in his first year with the club, after scoring 56 in the first innings. Most of his runs came through the offside, but when Hogan dropped short he pulled him over square leg for six.
After scoring 76, Crook was bowled, heaving at Smith, who then had Vasconelos caught at slip for 79. The tail surrendered in their quest for quick runs, before Wakely declared two overs before tea. Glamorgan had 33 overs to face in the evening session, and after a promising start, were soon 54 for2 .Nick Selman gave cover point a simple catch from Procter's second ball, then Jack Murphy, shortly after being struck on the helmet, guided one from Buck to third slip.
Usman Kahwaja after his century in the first innings, began by striking four boundaries, and followed by taking two more fours from Buck's third over. Owen Morgan was more circumspect, but played every ball on merit, and the third wicket pair soon shared a fifty- run stand.
After scoring 38, Kahawaja was caught by Vasconelos at short leg, when the Australian struck the ball firmly off Prasanna, only to see the fielder the fielder juggle with it three times before eventually holding on. Prasanna then took his second wicket when Morgan's push was deflected by first slip to second with Glamorgan almost dead and buried.