Michael Brown scored 93 as Hampshire built a commanding lead to frustrate Notts on day three at Trent Bridge.
Graeme Swann denied Brown his century when he was given a debatable lbw decision but dropped catches and resilient batting allowed Hampshire to cruise to 376-5 at close of play.
Chris Benham made 66 before falling victim to Samit Patel, his only breakthrough in 24 economical overs, and Sean Ervine edged to Will Jefferson at slip off Mark Ealham, the catch held at the second attempt.
"I expect Hampshire to bat on and we'll be chasing four hundred plus off around 80 overs," said Notts Director of Cricket Mick Newell.
"We looked tired and weary today and made mistakes in the field but we have to have a go tomorrow."
Elsewhere, Durham declared at 500-8 before making solid inroads into Kent’s top order, dramatically increasing the likelihood that only a win will secure the Championship for Notts.