Yorkshire 243 (Bess 54, Abbott 3-47, Wheal 3-47) and 34 for 1 (Kohler-Cadmore 16*, Hill 10*, Wheal 1-16) lead Hampshire 163 (Vince 49, Coad 3-29, Thompson 3-35) by 114 runs
Yorkshire's bowlers put their side in full control of the LV = County Championship clash against Hampshire on a day of White Rose dominance at the Ageas Bowl.
Victory for either team would greatly enhance a push to be in the title mix, but it was the visitors who seized the initiative as Hampshire were bowled out for 163 having earlier dismissed the visitors for 243 before lunch.
Yorkshire closed the day on 34 for 1 in their second innings - an imposing-looking lead of 114 - despite losing Adam Lyth for seven before the close.
The visitors added 46 to their overnight total of 197 for 6, missing out on a second batting point by just seven runs, as Mason Crane mopped up the tail.
Dom Bess top scored with a potentially priceless 54 before playing on to Keith Barker after Jordan Thompson had departed to the second ball of the morning from Brad Wheal.
Crane then trapped Matthew Fisher and Ben Coad lbw to wrap up the innings and leave Hampshire's batsmen with a tricky 35 minutes to negotiate before lunch.
It was a task they failed miserably as the fired-up Yorkshire bowlers ripped through the top order with Ian Holland falling for a first-ball duck to Coad before Joe Weatherley edged Fisher behind to leave Hampshire reeling at 1 for 2.
Nick Gubbins looked in decent touch as he unfurled three boundaries only for Coad to find the edge of his bat and Harry Brook pouched the catch at slip as Hampshire limped to lunch on 29 for 3.
When play restarted the murky skies that had enveloped the ground since day one lifted as sun briefly broke through the clouds to create the best batting conditions of the match.
In an encounter where run-scoring has been at a premium, James Vince showed his class with two boundaries from the first two balls he faced to raise hopes of a Hampshire rebuild.
Yorkshire were convinced they had their man on 35 when Vince was struck on the pad by opposite skipper Steve Patterson with a ball that looked destined for middle and off-stumps. But umpire Nigel Llong kept his finger down, much to the dismay of the fielders, who then saw the elegant right-hander crunch the ball to the boundary two deliveries later.
Yorkshire finally got the vital breakthrough when Vince, who had played a relatively risk-free innings, changed tack when on 49 only for his attempt to lift a short ball from Fisher over the rope finding the hands of George Hill.
Vince's exit sparked a collapse of 6 for 37 as Tom Alsop, who soaked up 96 balls for 12 runs, saw his torturous vigil ended by a peach of a delivery from Bess that clipped his off-stump.
The impressive Thompson picked up the wickets of Liam Dawson, Barker and Crane either side of tea with Bess grabbing his second victim when Lewis McManus was smartly caught off his boot by Harry Duke.
Wheal and Kyle Abbott added some valuable runs in a last-wicket stand of 40 before Coad wrapped up the innings to finish with 3 for 29.