Nottinghamshire batsman Alex Hales struck an impressive century but Hampshire's evening wickets evened the score to 301 for six on day one at the Ageas Bowl.
England man Hales classily reached fifty from 108 balls before only needing 48 more deliveries to reach three figures in this LV= County Championship match after smashing 236 against Yorkshire last week.
Having been put in by Hampshire skipper Jimmy Adams on an overcast but bitterly cold morning, the Nottinghamshire opening pair of Steven Mullaney and Brendan Taylor started strongly.
The duo put on 61 for the first wicket against a mature home attack - whose fast bowling quartet of James Tomlinson, Andre Adams, Gareth Berg and Sean Ervine's combined age totals 137.
As the seamers writhed, Adams turned to left-arm spinner Danny Briggs, who collected a wicket with his first ball - Taylor bowled through the gate.
Alex Hales' imperious start to the season continued. #HantsvNotts report from @bracecricket: http://t.co/jmyZrkNHngpic.twitter.com/HqxrUHCWZ8
— Nottinghamshire CCC (@TrentBridge) April 26, 2015
Opener Mullaney reached his patient first fifty of the season in 138 balls, while Hales brought up his milestone in a more brisk manner.
The pair recorded the second fifty partnership of the game - putting on 84 for the second wicket under the floodlights.
Ervine made the important breakthrough of Mullaney - his 200th first-class wicket for Hampshire - as the Nottinghamshire batsman chased a wide delivery to a somersaulting Adam Wheater.
Hales had a scare on 84 when he offered a sharp chance to Ervine at first slip, which was the only fright in a near-perfect knock.
He is the highest run scorer in Division One this season - with 411 runs after his strong start to the season - and he brought up his second three-figure score of the season with a thick outside edge - his 20th boundary of the day.
Hampshire's fourth wicket of the evening session! Chris Read (4) the man out & Notts are 267-6: https://t.co/BLiHqvIByR#LVCC
— Hampshire Cricket (@hantscricket) April 26, 2015
Wickets fell around the serene Hales as James Taylor top-edged a sweep behind for 10, before Samit Patel and Riki Wessels identically edged to second slip Liam Dawson off Adams and Berg.
Former Middlesex strike bowler Berg claimed his second wicket two overs into the new ball when Nottinghamshire captain Chris Read mistimed a pull stroke into the leg side.
Hales ended the day unbeaten on 136 frustrating Hampshire in the twilight of the day with Will Gidman 22 not out - the pair putting on an unbeaten 40 for the seventh wicket.
Hampshire need early wickets in the morning to gain the upper hand going into their first innings on day two.
Hales was pleased with how the day went and said: "Its been a good day for me and the team. We would have ideally liked to have fielded first, there was a little bit in the wicket but once the innings progressed it got a bit easier to play.
Dale Benkenstein reflects on day one v Notts at @TheAgeasBowlhttps://t.co/awoBKUPzcD via @audioBoom
— Hampshire Cricket (@hantscricket) April 26, 2015
"It is a purple patch, I'm really enjoying my cricket at the moment. I've got to not get complacent and keep churning out runs when I'm in this form.
"The plan is the bat as long as we can tomorrow and push 350 or 400 and get those extra points. If we come out and stick the ball in the right areas there is still plenty in the wicket to get a result."
Hampshire first-team coach Dale Benkenstein said: "I think they have the advantage, we would have liked to have bowled them out for under 300.
"There was enough in the wicket, but Hales batted very well.
"We bowled well in patches. I don't think we put the ball in the right areas for long enough today.
"Similarly to the Sussex game we had a lot of bad luck, a lot of balls just went past the edge.
"We would have batted if there was a bit of sun around. I still think that the conditions were as good as it gets for our seam bowlers."