Northamptonshire 369 (Keogh 172, Broad 56*) beat Essex 211 (Westley 49, Sanderson 3-17) and 119 (White 5-57) by an innings and 39 runs
Northamptonshire seamer Jack White rounded off the LV= Insurance County Championship campaign with a five-wicket haul to ensure his relegated side bowed out of Division One in style by crushing runners-up Essex.
White, who received the Northamptonshire supporters' player of the season award during the lunch interval, achieved his century of first-class wickets as the visitors were hustled out for 211 in their first innings at Wantage Road.
That snuffed out Essex's hopes of denying Surrey another title - and, having been put in again, they promptly collapsed to 119 all out, with Paul Walter's pugnacious 73 from 53 balls their only significant contribution.
White claimed the final wicket to finish with five for 57 - his 50th Championship scalp of the season - while former England captain Sir Alastair Cook made just six in what could be the final innings of his illustrious career.
Essex resumed on 125 for four, but their already slim hopes of amassing the runs required to prolong the title race were dented further as Tom Taylor's first ball of the morning sent two of Walter's stumps flying.
White and Ben Sanderson both found some unpredictable bounce from the David Capel End, but it was a half-volley by the latter that secured his landmark 100th wicket when former Northamptonshire team-mate Adam Rossington drilled to mid-on.
Essex skipper Tom Westley applied himself diligently, but he then got stuck on 49 and was eventually undone by a beauty from opposite number Luke Procter that pitched, left him and took a faint edge through to Lewis McManus.
Procter pinned Simon Harmer leg before to finish with figures of three for 47, but Umesh Yadav opted to throw the bat and rattled up 24 from 18 deliveries, playing some delightfully wristy shots as well as lifting White for a leg-side six.
Sam Cook joined in, steering Taylor for successive fours to lift the Essex total above 200 but Yadav holed out to deep midwicket before last man Jamie Porter was castled by Taylor to confirm the Championship pennant would remain in Surrey's possession.
Having not managed to supplement his three wickets from the previous evening, Sanderson made amends for that in the first over of the follow-on, with Nick Browne misjudging a ball that jagged back and careered into his off stump.
Lunch offered Essex some respite - but the carnage continued after the interval and within seven overs of their second innings, the visitors had collapsed to 13 for five, with Sanderson and White claiming another two wickets apiece.
Those included Cook, caught behind nibbling outside off stump at Sanderson, while Justin Broad's tumbling cover catch accounted for Westley and Emilio Gay pouched two at second slip.
Walter launched a bold counter-attack with a series of front-foot drives, while Rossington kept him company for 35 minutes despite playing just a single scoring stroke as the pair shepherded Essex to 50.
Taylor broke the partnership with an unplayable delivery that kept low and seamed back to uproot Rossington's off stump, but Walter kept going and advanced to his half-century with a cover boundary off White.
Rob Keogh's first over of off-spin cost 19 runs, with Walter twice dispatching him over the stand before White eventually got his man, tempting the left-hander to pull a short ball and top-edge to Saif Zaib in the deep.
That paved the way for White to apply the finishing touch and he bowled Harmer before clipping Yadav's off bail to wrap up Northamptonshire's second win of the season - their first by an innings in more than two years.
