Kyle Abbott finished with match figures of 17-86 as Hampshire dealt a huge blow to Somerset’s County Championship title hopes with victory at the Ageas Bowl.
The ex-South Africa paceman followed his first-innings 9-40 with 8-46 as Somerset were 144 all out, chasing 281.
His match figures, which helped his team to a 136-run win, are the best by any Hampshire bowler ever and the fourth best in Championship history.
Hampshire captain James Vince had earlier made 142 in their 226 all out.
The result has left Somerset needing to beat nearest rivals Essex in their final match, which gets under way on Monday, 23 September.
Having started this round of fixtures with an eight-point advantage at the top of the Division One table, the West Country side find themselves 12 points adrift in second after Essex beat Surrey by an innings and 40 runs.
The title will now be decided at the County Ground in Taunton in what promises to be a thrilling finale to the season.
Somerset’s chase at the Ageas Bowl looked a tough one even before Vince added 40 to his overnight 102 to extend Hampshire’s advantage to 280.
The England batsman, ably supported by Abbott (25), struck 22 fours before eventually being caught behind off Craig Overton (3-74).
Somerset openers Steven Davies (51) and Murali Vijay (29) then looked relatively untroubled in seeing them to 86-0, briefly raising their hopes of pulling off what had looked an unlikely victory.
But the departure of India batsman Vijay sparked another top-order collapse, as seven wickets fell for just 14 runs to completely turn the contest on its head.
Having bowled too short before lunch, Abbott pitched the ball up and wreaked havoc during the afternoon session, with Tom Banton and George Bartlett both trapped in front playing across the line and Davies (51) edging to the slips to give him three wickets in four balls.
Before Liam Dawson took the penultimate wicket, of Roelof van der Merwe, Abbott was in with a chance of returning the second-best first-class figures of all time – second only to Jim Laker’s 19-90 for England against Australia in 1956.
But he did at least bowl last man Josh Davey to give him 17 wickets, the best Championship haul since 1925 – and he now has 68 this season at a cost of only 15.70 each.
Best match figures in Championship
17-48 C Blythe, Kent v Northamptonshire 1907
17-56 C Parker, Gloucestershire v Essex 1925
17-67 A Freeman, Kent v Sussex 1922
17-86 K Abbott, Hampshire v Somerset 2019
17-89 WG Grace, Gloucestershire v Nottinghamshire 1877
17-89 F Matthews, Nottinghamshire v Northamptonshire 1923