Hampshire 462 (Gubbins 201*, Dawson 109, Vince 57, Virdi 5-133) and 3 for 0 lead Worcestershire 273 (Brookes 132, Roderick 94, Dawson 5-88, Abbas 4-27) by 192 runs
Nick Gubbins equalled his first-class best before Ethan Brookes scored a scintillating maiden Vitality County Championship century but couldn't prevent a hefty Hampshire lead.
Gubbins shone to reach 201 as Hampshire picked up maximum batting points in their improbable title charge, before Mohammad Abbas ran rampant to leave the visitors 61 for 5.
Worcestershire's Brookes and Gareth Roderick countered in a flurry of sweeps and high-quality batting to put on 196, with scores of 132 and 94 individually to confirm their side's safety in Division One.
But Liam Dawson claimed his fifth five-wicket haul of the summer to boast a 189-run first-innings lead, however Hampshire did not enforce the follow-on - instead closing the day on three without loss.
Dawson and Gubbins began the day by setting a fifth-wicket partnership record for Hampshire against Worcestershire - beating the 209 between Jim Bailey and Neville Rogers in 1946.
The stand reached 220 before Dawson advanced, swatted and skied Tom Taylor to Adam Hose, to begin a hair-raising 10-over spell where Hampshire attempted to reach 450, while losing regular wickets.
Gubbins continued his reign and reached the second double-century of his career in 315 balls with a powerful strike through the leg side.
But around him, Surrey loanee Amar Virdi took advantage of the aggression to pick up his first professional five-for since 2021.
Tom Prest chipped to midwicket to give Taylor his fourth, before off-spinner Virdi got one to turn sharply to pin James Fuller, found Felix Organ slogging to deep midwicket and Kyle Abbott leg before when going back.
It was left to Abbas to clip off his legs to the boundary to reach 450 and a fifth batting point before he left Gubbins unbeaten when he edged to second slip.
Worcestershire's response continued the wicket rush as Abbas produced one of his spells where he has the ball on a leash.
Jake Libby was done between bat and pad to a ball that nipped in and took the top of the off stump, before Kashif Ali tried to cover his stumps but edged to first slip.
The Pakistan international produced another teaser by holding one outside off stump for Rob Jones to nick off, before adding an Adam Hose lbw after lunch to leave Worcestershire 30 for 4.
Dawson began his haul with a smart piece of field movement to switch Fletcha Middleton from short leg to short mid off, before some extra bounce saw Brett D'Oliveira glove one to the re-placed Middleton.
Roderick had weathered the storm from his end and found a bullish Brookes keen to score quickly - his second time past fifty in 52 balls has he quickly zoomed ahead of his top-order partner's scoring rate.
With Dawson, and Felix Organ, in operation for much of the innings, Brookes took to sweeping to survive and score. He played 44 variations on the shot during his innings. It brought him 13 boundaries and 71 of his runs.
His century came in 128 balls and was celebrated with great gusto on and off the field, as he and the increasingly attacking Roderick broke a 124-year record for the sixth wicket for the Pears versus Hampshire - eventually ending on 196.
By getting to 250, tied with their three bowling points, Worcestershire secured their Division One status for another season.
But that positivity melted into a sticky collapse - with the last five wickets falling for 16 runs.
Roderick was leg before to Organ - who wrestled things back after an expensive opening few overs to only go at sixes in the face of jeers from spectators - before Dawson took over.
Brookes died by the sweep when he picked out deep square, Logan van Beek and Virdi were lbw before the innings ended with Joe Leach pouched at slip.
Without Roderick and Brookes' stand, the next highest partnership was worth 31, and only D'Oliveira scored more than four runs.
Hampshire's didn't make them go again, and Hampshire openers Middleton and Toby Albert went through six overs unscathed.