Kyle Abbott’s maiden Specsavers County Championship 10-wicket haul in a match set up Hampshire’s fourth win of the season, and all but end Somerset’s title charge.
Abbott backed up his five scalps in the first innings before celebrating six for 40 to bowl Somerset out for 116 and end the match with analysis of 11 for 71.
Jimmy Adams then confirmed the victory with a an unbeaten 25 – as the home side chased down 75 to win by six wickets.
Somerset will have to wait until the conclusion of Surrey's fixture with Worcestershire to find out if they are still in with a chance of lifting the Division One trophy this season.
Somerset needed just 10 balls to wrap up the Hampshire first innings, as Fidel Edwards chipped a simple caught and bowled back at Craig Overton.
That gave Hampshire a 42-run first innings advantage, after 19 wickets had fallen on the first day – an Ageas Bowl record.
The conditions were still just as conducive for the fast bowlers, with grey clouds, a grass tinged pitch and the floodlights on.
Trescothick, who made a dogged half century, watched from the non-striker’s end as his top order teammates slipped to 20 for four, after an Abbott masterclass in seam bowling.
Ben Green was first to depart, to Abbott’s third delivery, as he was indecisive to a ball which nipped back.
Abbott found another delivery to jag back, with extra bounce, to catch the inside edge and fly through to Tom Alsop behind the stumps.
James Hildreth and Tom Abell were Abbott’s next victims, the former pinned lbw and the latter castled.
But Trescothick continued in a watchful manner, copying Sam Northeast’s successful style which accumulated 53 on the first day.
He added 41 for the fifth wicket with Steven Davies as Abbott and Dale Steyn made way for change bowlers Edwards and Ian Holland.
But the Steyn and Abbott marriage returned to resume the wicket taking, with Davies caught at first slip off Steyn and Abbott bowling Lewis Gregory – to celebrate his second five-wicket haul of the match.
Craig Overton was another prey of an Abbott angled in delivery as he flicked behind, where Alsop pulled off an exquisite flying catch to his right, before his brother Jamie slapped Steyn to Liam Dawson at point.
Yet Trescothick was still at the crease and turned his dial to stroke play during a 25-run stand with No.11 Josh Davey.
The former England opener bought up two landmarks with a pair of sixes – the first his 26,000th first-class run, the second to take him to a 122-ball half century.
He eventually departed to give Steyn, a fast bowler that had dismissed him twice in Test cricket, his 600th first-class wicket as he chopped on.
That set Hampshire 75 runs to win, but Craig Overton wasn’t going to make it easy for the hosts.
The right-arm fast bowler found opener Oli Soames tickling behind off his legs and then snared Joe Weatherley and James Vince within three balls.
Weatherley pushed behind before Vince completed his pair when he slashed to backward point – leaving Hampshire 21 for three and still needing 54.
Adams, along with Northeast, alleviated some of the pressure with a 25-run stand, but the nerves returned at the Ageas Bowl when the latter edged to second slip.
But Adams, who will retire at the end of the season, dragged his side across the line with Tom Alsop, at 4pm on the second day.
Kyle Abbott claimed his third five-wicket haul in as many Specsavers County Championship games before Sam Northeast’s half century edged Hampshire into a slender first-innings lead on a wicket-heavy first day against Somerset.
South African fast bowler Abbott has now taken 24 scalps in the four matches since the Championship returned from the Vitality Blast.
And Abbott used the seam friendly conditions to his advantage to post figures of five-for 31 to help Hampshire bowl Somerset out for 106.
Hampshire then lost nine wickets of their own, taking the day one wicket tally to 19, but Northeast handed his side a 36-run lead with a patient 53, with Hampshire ending on 142-9.
Tom Abell won the toss and elected to bat, which at the time appeared a sensible move with blue skies and a dark coloured pitch, albeit covered by a short layer of grass, although hindsight now suggests differently.
Marcus Trescothick seemed to back the decision as he threaded three eye-catching drives through cover and mid-off in Abbott’s first over.
But Abbott got his revenge in his following over as he found the outside edge of Trescothick’s bat, with wicketkeeper Tom Alsop completing a smart catch.
Azhar Ali and Ben Green provided a short 28-run stand for the second wicket before Ian Holland’s miserly bowling dismissed the pair.
Holland’s eight overs of medium pace boasted figures of two-for five, with Ali leg before to a fullish delivery which swung in gently, before Green was bowled attempting a straight drive.
James Hildreth and Abell both departed with the score on 71, which dislodged the block and started the Jenga tower style collapse.
Hildreth drove Abbott to Jimmy Adams at second slip before Abell pushed Dale Steyn to Holland at first slip.
After lunch, Abbott had the ball on a string and ran in with the confidence each ball could bring a wicket, as Lewis Gregory, Steven Davies and Jamie Overton found to their disadvantage.
Gregory was lbw to a ball which stayed relatively low, Davies was yorked before Overton was leg before to complete Abbott’s 23rd first-class five-for.
Overseas star Steyn quickly wrapped up the tail as both Craig Overton and Jack Leach edged behind - Somerset had lost their final six wickets for 35 as they were bowled out in 37 overs.
Hampshire’s reply followed a similar pattern of seaming deliveries causing the batsmen trouble.
Oli Soames, on his home Championship debut, lasted two deliveries before Josh Davey struck him on the pads.
Joe Weatherley followed his opening partner as Gregory pinned him lbw, before the seamer bowled a loosely driving James Vince two balls later leaving the hosts 12 for three.
Adams provided some much-needed resistance, during a 47-run stand with Northeast, with an assured 31 from 75 balls but lost his concentration in the last over before tea to gently dangle at Davey, and edge behind.
Northeast took over Adams’ rigidity, as Alsop was lbw and Holland was bowled – both by Jamie Overton – to leave Hampshire 68 for six.
The former Kent batsman refused to take risks while sliding his side out of danger and towards a first innings lead – his half century arriving in 90 balls.
Northeast, with Liam Dawson, accumulated 56 between them for the seventh wicket before the latter was caught and bowled by Green for a hard-working 31.
Northeast was dropped on 53 by Gregory at third slip, but departed when he was bowled by Jamie Overton.
Steyn was castled by Davey but Hampshire remained nine down at the close.