Adrian Dale cracked the first double-century of the CricInfo Championship season as Glamorgan turned the screw against their fellow first division newcomers Northamptonshire.
The Welsh county had dominated proceedings on the opening day, and continued in the same vein as their overnight 339-4 became 548-6 declared. Dale hit 204 in six hours, featuring 31 boundaries, and posted a record-breaking 248 for the fifth wicket with Keith Newell (103).
Northants' reply then ran into trouble and they struggled to 181-5 from 50 overs at the close, still needing a further 218 to avoid the follow-on with two days remaining.
Dale joined Maurice Turnbull, Roy Fredericks and Steve James in the ranks of Glamorgan's double-centurions against Northants, and also passed 10,000 first-class runs in the course of his 276-ball knock.
Newell proved an admirable foil for his acting-captain and completed his first Championship hundred since joining the Welsh county from Sussex two years ago. He and Dale eclipsed Glamorgan's previous fifth-wicket best against the Midlanders - 206 by Bernard Hedges and Jim Pressdee at Northampton in 1961 - before Jason Brown broke through, yorking Dale.
Mike Hussey's throw from backward point ran out Newell to end his stay of four hours 40 minutes, including 16 fours, and the declaration came soon afterwards.
Northants then lost the wickets of Hussey, Mal Loye and Jeff Cook for 53 before tea, and with Robert Croft removing the Swann brothers in the final session it was left to Russell Warren (72 not out) to keep the home side afloat.