Warwickshire lost their last seven wickets for the addition of 58 runs in less than 16 overs due to inspired bowling from Hussain (five for 48), before the Cidermen chased down a victory target of 271 thanks largely to Kieswetter's superb 152, which included 14 fours and seven sixes.
With 12 runs needed and five wickets in hand, a late collapse put the result back in doubt at Taunton as Keith Barker (six for 40) took four quick wickets but Peter Trego finally hit the boundary that secured a one-wicket success and inflicted a first loss of the campaign on Warwickshire.
In another nailbiter, Australian Steve Magoffin proved the match-winner for Sussex in a gripping climax to their contest against Durham at Arundel.
He took six for 22 as Durham were dismissed for 93 in their second innings, then scored 23 not out to see his side to a two-wicket win.
Needing 94, Sussex looked doomed when Magoffin went to the crease at 50 for seven, but Kirk Wernars helped him put on 23 before James Anyon knocked off the remaining runs.
Nottinghamshire seamer Andre Adams became the first bowler to take 50 County Championship wickets this season as his side's clash with Surrey at Trent Bridge fizzled out into a draw.
After two days has been lost to rain, the hosts advanced their first innings score of 178 for five to 328 all out with the help of a 145-run stand in 34 overs between Chris Read (98) and Adam Voges (59), with Stuart Meaker picking up five for 78.
In reply, Jason Roy blasted an entertaining 83 and Rory Burns (79) struck a maiden Championship half-century before Adams returned from a wicketless first spell to finish with four for 51 as Surrey closed on 252 for six.
Nottinghamshire are now just a point behind pacesetters Warwickshire in the standings, with Somerset a further seven points back in third.
Leicestershire's bowlers held their nerve to deny Gloucestershire victory on an exciting final day of the LV= County Championship Division Two clash at Cheltenham.
Set 222 to win in 53 overs, Gloucestershire looked to be favourites following half-centuries from skipper Alex Gidman and Dan Housego.
Needing 47 off the final 10 overs, Gloucestershire faltered badly at the death, losing four quick wickets before putting up the shutters and settling for the draw. They reached the close on 209 for eight, just 13 runs short of their target.
Leicestershire were indebted to veteran South African spinner Claude Henderson, who bowled unchanged from the Chapel End after tea to return figures of four for 80 and undermine the chase.
The top-of-the-table showdown between Derbyshire and Yorkshire ended in stalemate and frustration when no play was possible for the third day running at Chesterfield.
It means both teams take six points from the contest and leaders Derbyshire remain 25 points in front of one of their promotion rivals who held a slight advantage in this game before the weather intervened.
On a day of two declarations, Essex and Hampshire were locked in an intriguing struggle for victory in their battle at Chelmsford. Faced with a target of 360, Essex will go into the final day on 102 for two, with Billy Godleman seeking to add to his 37 that has so far spanned three hours.
Finally, Glamorgan's batsmen showed their resolve and a willingness to battle on day three at Canterbury, digging in against Kent to reach 264 for seven and improve their chances of avoiding the follow-on.
Kent declared on their overnight first-innings total of 456 for nine when play finally started at noon, setting the Welsh county 307 to avoid the follow-on, and by stumps the visitors were only 43 short of their target with three first-innings wickets intact.