Ian Holland and Tom Alsop each scored centuries as in-form Hampshire dominated the opening day of the LV= Insurance County Championship clash with Gloucestershire at the Ageas Bowl.
Hampshire closed the day on 292-3 to continue their excellent start to the season, with Alsop unbeaten on 127 at the close with nightwatchman Mason Crane yet to score.
Sam Northeast was dismissed for 24 in the penultimate over of the evening when he was caught down the leg-side by James Bracey off Matt Taylor, .
Both sides went into the game on the back of victories in their opening two matches.
However, the visitors were rocked before the match by news they could not field all-rounder Graeme van Buuren due to delays in his paperwork after complications around Brexit changed his eligibility status to that of an overseas player.
South African Van Buuren scored a match-winning century in the win over Surrey two weeks ago and is also the side's front-line spinner.
But he had to be left out of the team after the club received the news with West Indies batsman Kraigg Braithwaite and Australia quick Dan Worrall already named in the team.
Holland followed up on the unbeaten 146 he chalked up against Middlesex last week with a patient knock of 114 on a good batting pitch that offered little for the bowlers.
The visitors, who also took the impressive scalp of Somerset last week, made an early breakthrough when Dominic Goodman struck with his first delivery of the match.
The twenty-year-old seamer, who is still a student at Exeter University, took three wickets on his debut at Taunton last week and he trapped Joe Weatherley lbw for just eight, leaving the opener as the only player in the Hampshire top-six not to pass at least 100 this season.
With little in the slow-paced surface to offer encouragement to the bowlers, Worrall did manage to find the edge of fellow Australian Holland's bat when he was on 77, only for Braithwaite to put down the most straight-forward of slip catches.
After resuming after tea on 90, Holland chalked up his third career century with a flick through square leg off Josh Shaw.
Alsop's second century of the campaign was punctuated with two glorious straight drives down the ground and a series of venomous cut shots to the boundary as the 25-year-old brought up three figures for the fourth time in his career.
Worrall finally got the breakthrough when he ended the 228-run stand for the second wicket when he trapped Holland on the back of his crease.
James Bracey struck back for Gloucestershire in response to Hampshire's big first innings total, led by Tom Alsop's magnificent 149 and half-centuries for Liam Dawson and James Vince.
The 23-year-old and Kraigg Brathwaite put on 88 for the second-wicket before the West Indies opener fell late in the day for 60 to leave the visitors on 114-2 at the close having earlier bowled out the hosts for 470.
Bracey, who was named as a reserve batsman for England's tour of Sri Lanka earlier this year, was 46 not out against a strong Hampshire attack spearheaded by Mohammed Abass, Kyle Abbott and Dawson, with Tom Lace yet to score.
Things looked ominous for Gloucestershire when skipper Chris Dent fell for six to Abbas to a ball that kept low and pinned him on the crease.
But Brathwaite and Bracey, watched from the boundary by Trescothick after scoring 118 and 83 in the win over Somerset last week, calmly saw off the new ball.
With the pair looking relatively untroubled, Dawson then managed to get a ball to spit off the surface and had Brathwaite caught by Lewis McManus.
It led to a tense passage of play but Bracey and Lace survived despite the presence of several fielders around the bat for Dawson's final three overs.
After starting the day on 292-3, Hampshire lost nightwatchman Mason Crane early before Tom Alsop fell before lunch for a superbly-made 149 - one shy of his highest score.
The 25-year-old, who made a century against Leicestershire two weeks ago, struck 19 fours in his 290-ball vigil before being caught down the leg-side by Bracey off Ryan Higgins.
Vince hit a trademark sumptuous cover-drive to the boundary before lunch on his way to his half-century.
The Hampshire skipper showed glimpses of class, including successive fours off the bowling of Dan Worrall.
However, in a dramatic over, Vince inside-edged the very next delivery to Bracey with McManus then controversially dismissed to what appeared to be a bump ball, putting Worrall on a hat-trick.
The Australian seamer who was the pick of the visiting bowlers, claimed his fourth wicket when Abbott was struck on the pad as the hosts lost 3/16 after the restart.
Dawson smashed two sixes and five fours on his way to an entertaining 65 before being cleaned up by Higgins, who then bowled Abbas to finish with 4-78.
Hampshire enforced the follow-on late on day three at the Ageas Bowl after a dramatic final-session collapse saw Gloucestershire dismissed for 320 with spin twins Liam Dawson and Mason Crane taking five wickets between them after tea.
Gloucestershire closed on 14-0 after Kraigg Brathwaite and Chris Dent survived the last six overs, but trail the home side by 136, going into the final day having missed the chance to make Hampshire bat again by just one run.
The visitors looked to have frustrated the hosts' push for a third successive victory on a largely attritional day thanks to a slow pitch, before the game burst into life after tea when they lost 5-37.
An excellent 73 from Ryan Higgins in a 76-run stand for the sixth wicket with George Hankins, had frustrated Hampshire after they had bowled well early in the day.
Having resumed on 114-2, Tom Lace and James Bracey withstood some testing bowling from Kyle Abbott and Mohammed Abbas, who finished with 4-41, in the first hour of the morning.
However, Lace, having played with great restraint, couldn't resist playing at a rare wide delivery from Abbas and edged behind to Lewis McManus for 20.
Bracey, whose brilliant early season form has put him in the frame for an England call-up, played beautifully for his 65.
However, he will not want to see his dismissal to Abbas again any time soon after his stumps were rattled by a ball he played no shot to, in a rare lapse of judgement in his four-hour stay at the crease.
Ian Cockbain was then bowled by Abbas for 24 after lunch before Higgins and Hankins guided their side safely to tea at 271/5 with the draw looking the most likely outcome.
But Crane then took three quick wickets when he trapped Hankins lbw for 31, rattled the stumps of Higgins after he bottom-edged an attempted sweep, before dismissing Dan Worrall. for five.
Dawson, who toiled away for 41 overs, got the reward his efforts deserved when he dismissed Josh Shaw and Matt Taylor as Gloucestershire fell agonisingly short of not having to bat again.
A stubborn last-wicket stand from Josh Shaw and Dominic Goodman salvaged a dramatic draw for Gloucestershire against Hampshire on an absorbing final day at The Ageas Bowl.
Hampshire had looked on course for a third successive LV= County Championship victory when the pair came together with 22 overs of the day remaining and their side leading by just 11 runs.
However, Goodman and Shaw soaked up 106 balls between them in a 36-run stand to frustrate the hosts who had ripped through the middle and lower order in a devastating spell after tea.
Goodman, 20, who is still a student at Exeter University and playing only his second first-class match, was unbeaten on nine having faced 39 deliveries before scoring, with Shaw 23 not out after an hour and 20 minute stint at the crease.
Gloucestershire, who were made to follow on late on Saturday, started the day on 14-0 with Chris Dent and Kraigg Brathwaite surviving the opening 40 minutes from Kyle Abbott and Mohammad Abbas with few alarms.
But it was first-change bowler Wheal who made the breakthrough when he found the edge of Dent's bat and Liam Dawson took a brilliant juggling catch in the slips to dismiss the visiting skipper for 10.
In the very next over Brathwaite undid all of his hard work when he tried to smash Dawson back over his head but instead picked out Abbott at deep mid-on.
Dawson then snared the in-form James Bracey for his first single-figure score of the season when he tried to drive the ball out of the foot marks but could only divert it to Ian Holland at slip to leave Gloucestershire in deep trouble at 50-3.
Tom Lace and Ian Cockbain steadied the ship until an hour after lunch when the former Middlesex batsman, who'd played well for his 38, was brilliantly caught at slip by Joe Weatherley off Wheal.
But Cockbain, a white-ball specialist, playing his first four-day match for three years dug in manfully for 36 from 122 balls as Gloucestershire lost just one wicket in the middle session.
Abbott struck immediately after the restart when he dismissed Cockbain and the dangerous Ryan Higgins before Wheal snared George Hankins and Dan Worrall in successive balls.
Mason Crane then trapped Matt Taylor lbw leaving the hosts pondering a memorable victory, but Shaw and Goodman held out to deny James Vince's side.