Warwickshire's captain took six for 16 as the visitors were all out for 97 in reply to 391 for nine declared.
Following on 294 behind, Nottinghamshire made a much better fist of it and reached the close on 116 for one, with Ben Duckett unbeaten on 71, but they have plenty more work ahead on the final day to avoid defeat.
On a pitch offering some, but not extravagant, turn, Patel will aim to continue his purple patch. Having followed match-figures of 12 for 89 against Surrey last week with six for 16, his combined analysis from three successive championship innings is 75.4-39-105-18.
Those wickets took his first class wicket-haul for the county that he first joined in 2009 to 440 at 25.31 - an exceptional effort of sustained excellence in an era when the input of overseas players to counties tends to be fleeting.
The New Zealander's skills sent Nottinghamshire's first innings from the relative comfort of 69 for two into freefall as they lost five wickets for ten runs in 59 balls. He exploited the pressure the visitors were under after Adam Hose completed his maiden first-class century - 111 from 202 balls with 14 fours and two sixes - in the morning.
After Warwickshire resumed on 311 for seven, they added 80 in 16 overs. Patel made a brisk 23 before playing on to Luke Fletcher, then Hose and Liam Norwell (34 not out, 43 balls) added 62 before Hose holed out to deep mid-wicket in pursuit of a third successive four off Samit Patel.
Nottinghamshire lost Ben Slater, caught at third slip off Olly Hannon-Dalby, before lunch and Ben Duckett, caught at mid on off Henry Brookes, shortly after the interval but at 69 for two there was no sign of the clatter ahead. Patel and Norwell then dovetailed to devastating effect.
Chris Nash (25, 41 balls) and Steven Mullaney edged Norwell into the slips while Patel had Joe Clarke caught at short leg, bowled Samit Patel and trapped Tom Moores lbw.
James Pattinson and Fletcher dug in to add four in 53 balls before the latter edged Patel behind. Two lbw verdicts, to dismiss Stuart Broad and Matt Carter, left the New Zealander with a six-for and Pattinson unbeaten on six after 83 minutes of noble resistance.
Second time around, Nottinghamshire lost Slater, caught behind, to Patel's sixth ball, but Duckett compiled a polished, 99-ball half-century and, with Nash, batted carefully to add an unbroken 76 up to stumps.