Steven Mullany scored 97 as Nottinghamshire recovered from a top order collapse to post 270 all out against Hampshire.
Hampshire reached 23-1 at the close after Darren Pattinson induced Dawson to edge to Chris Read but Mullaney's innings and a five-wicket haul from James Tomlinson made a sizable impact on proceedings.
A five-run opening stand between Neil Edwards and Bilal Shafayat gave Notts a poor start and Alex Hales, making his first LV= County Championship appearance of the season, went lbw for nought facing his sixth ball.
Samit Patel was caught behind for 11 bringing in Mullaney who prospered alongside Shafayat (14), Brown (42) and Read (22). Mullaney was dropped by Jimmy Adams at slip on 50 and made Hampshire pay for their mistake.
Paul Franks, crowned Nottinghamshire's Player of the Month at lunch, continued his remarkable start to the season with an unbeaten 57.
“I enjoyed the knock but I was gutted not to make three figures because I felt good and knew that the opportunity was there for me,” said Mullaney.
“I felt that the wicket ball was there to be hit for four but unfortunately for me I’ve flicked a long-hop to the wicket keeper.
“We needed to make a stand after going four down and Ali Brown and Paul Franks chipped in for us. We’d have taken 270 at the start of the day and we set ourselves a target of around 250 when we had some discussions at lunch.
“All four dismissals were good balls and that happens when it swings and seams at Trent Bridge. The lads at the top of the order want to get runs and if they can, then we’ll look to get past 400 in every innings.
“We’re happy, we’re full of confidence and we’re aiming to go five from five.”