Hampshire 367 and 39 for 2 (Gubbins 20*, Williams 2-12) trail Lancashire 484 (Jennings 172, Bell 99, Dawson 4-156) by 78 runs
Keaton Jennings quickly disproved a Utilita Bowl jinx with a fine century to ease Lancashire into a large first-innings lead over Hampshire.
Five batters - Nick Gubbins, James Vince, Tom Prest, Liam Dawson and Luke Wells - had scored fifties without converting to three figures in the first fixture at the newly renamed ground. But Jennings turned his overnight 85 into 172 with barely a moment out of shape, 21-year-old George Bell brilliantly accompanied him - but he was left cursing himself after running himself out for 99, with a maiden first-class century at his fingertips.
Lancashire were eventually bowled out for 484 - with Liam Dawson picking up 4 for 156 - boasting a 117-run lead. Hampshire lost two wickets to Will Williams before the close as they reached 39 for 2. Neither the pitch nor the Kookaburra ball have assisted the bowlers in any way shape or form, but batters have been able to make hay at the Utilita Bowl.
The only time Jennings had looked at ease during his seven-and-a-half-hour vigil had been on day two when he was dropped at point, when on 36, by Nick Gubbins. Otherwise, it was a 360-degree showcase of his skills, with the lack of movement from the fast bowlers not troubling him, and his renowned brilliance against spin made threats low.
The former Test opener reached his 28th first-class century in 234 balls with an effortless cover drive as he and Bell eased through the morning session. In fact, Hampshire's solitary moment of joy came when they thought James Fuller had produced an edge out of Jennings, but their celebrations were cut short by the lack of the umpire's finger.
Jennings moved through 150 - something six of his last seven red ball centuries have done - with Lancashire reaching 350 before the bonus points ended. That point will mean Lancashire will take one extra point if this ends in a draw.
The 40th over of the day finally ended the 166-run stand between Jennings and Bell, as Dawson pinned Jennings while he played a reverse sweep.
Bell was largely risk-averse throughout his innings but showed he was capable of driving attractively and adeptly finding gaps.
He wouldn't be rushed with his 50 coming in 132 balls, with a century seeming inevitable - despite seeing Dawson have Matthew Hurst caught at first slip and Tom Bailey leg before, having previously stood his ground after James Vince wrongfully claimed a catch.
The only time he looked skittish was in the 90s and taking off for a single - when one was needed for a fine first ton. A run was never really in the offering, something Jack Blatherwick recognised and sent him back but too late for Ian Holland to directly hit from point.
It was the second time that Bell had fallen in the 90 - having hit 91 against Middlesex last September - with a century surely not far away.
Dawson's tireless twirling away for 49 overs concluded by bowling Will Williams, before Fuller claimed his second of the innings when Blatherwick edged behind.
In 21 twilight overs under the lights, all of the visiting bowlers beat the bat countless times, but were rewarded with a pair of wickets. Williams tickled a defending Fletcha Middleton's outside edge and a swishing Ali Orr to give Lancashire a slight hope of forcing an unlikely win.
