Glamorgan's captain, Matthew Maynard, only brought on the off-spinner to bowl the day's first over to allow Steve Watkin to change ends. A wicket in his first over changed that thinking and some 18 overs later Croft had wrapped it all up with 5 for 33, his first five-wicket haul of the season.
If rain had not intervened during lunch and proceeded to wipe out the rest of the day's play, Glamorgan could have been well on the way to making Kent's future in this match a lot more uncertain.
As things stand, given the fragility of the Kent batting yesterday, a lead of 124 could be the foothills to a mountain of runs and the pitch can only become more helpful to Croft.
The England off-spinner is in fine form with bat and ball. Everything seems to be going for him so far this season. In all three of Glamorgan's Championship matches Croft has taken a wicket in his first over. Against Warwickshire and Yorkshire he took wickets with his first delivery. Alan Wells managed to delay the inevitable by a further four balls before padding up to one that drifted in to him.
Nigel Llong also fell leg-before, again padding up, this time to a quicker, straighter ball. For a while Mark Ealham and Graham Cowdrey dug in, 31 runs coming from them before Cowdrey pushed a little too far and was snapped up by Maynard at silly mid-off. Matthew Fleming was superbly taken by Croft off his own bowling and Martin McCague's valiant swat and swipe - he hit the only two boundaries to be taken off Croft, an edged four which almost knocked out Tony Cottey at slip and a huge six over mid-wicket - ended at extra cover.
And amid Croft's vintage display Darren Thomas found some life and line to dispatch Ealham, Paul Strang and Kent's captain, Steve Marsh.