In terms of balls faced

For Glamorgan

56 balls RDB Croft v Surrey at The Oval, 2002 (FPT)
57 balls TL Maynard v Northamptonshire at Colwyn Bay, 2009 (P40)
58 balls MP Maynard v British Universities at Cambridge, 1996 (B&H)
60 balls MP Maynard v Surrey at The Oval, 1997 (SL)
66 balls CA Ingram v Essex at Chelmsford, 2016 (RL)
68 balls H Morris v Kent at Canterbury, 1996 (B&H)

Against Glamorgan

46 balls GD Rose for Somerset at Neath, 1990 (SL)
48 balls DI Stevens for Kent at Swansea, 2017 (RL)
53 balls SW Billings for Kent at Canterbury, 2016 (RL)
61 balls JE Morris for Derbyshire at Heanor, 1989 (SL)

In terms of length of innings

For Glamorgan

62 mins MA Nash v Hampshire at Swansea, 1976 (B&H)
73 mins MP Maynard v British Universities at Cambridge, 1996 (B&H)

Against Glamorgan

51 mins GD Rose for Somerset at Neath, 1990 (SL)
67 mins MJ Prior for Sussex at Hove, 2006 (NL)
72 mins BD Julien for West Indians at Swansea, 1973 (F)