Will Smith's half-century helped Hampshire to 231-5 on a weather-affected first day against Derbyshire at the County Ground.
Smith made 70 before losing his wicket late on as Derbyshire's bowlers were made to work hard for their rewards in their first home Division Two match of the season.
Opener Michael Carberry's 45 had got Hants off to a good start while Liam Dawson contributed 39.
In other action on Sunday, David Payne was left frustrated as Glamorgan slumped to 47-6 against Gloucestershire in Cardiff before rain washed out more than two whole sessions.
Gloucestershire quick Payne was left waiting to bowl his hat-trick ball after he claimed the scalps of Murray Goodwin and Mark Wallace with the final two deliveries before the weather brought a halt to proceedings in the 20th over.
Payne, who left the pitch with figures of 3-14 from 4.4 overs, also claimed the wicket of South African batsman Jacques Rudolph for four as the home side collapsed.
No play was possible between Kent and Leicestershire as both teams were frustrated by rain on day one of their clash at Canterbury, as was the game at The Oval between Surrey and Essex.