Hampshire will face Glamorgan in the semi-finals of the YB40 after winning group B.
Giles White’s men – the defending champions – will have home advantage in next month’s contest.
Nottinghamshire host Somerset in the other last-four encounter.
England Lion Michael Carberry starred with the ball as Hampshire sealed top spot by winning at Derbyshire by 41 runs.
Carberry took three for 37 with his occasional off-breaks to send Derbyshire crashing to 178 all out in the 36th over, in reply to Hampshire’s 219 for seven built around 64 runs from skipper Jimmy Adams.
No other Hampshire batsman managed a 50 in difficult batting conditions.
But Chesney Hughes cracked 74 off 80 balls in reply.
The Falcons looked good with 112 needed from 20 overs but Hughes drove back a return catch to Liam Dawson.
Carberry then bowled Billy Godleman and Richard Johnson was run out by a direct hit from Mascarenhas.
Alex Hughes drove Carberry to mid off, Scott Elstone top edged a sweep and Wood grabbed two wickets in four balls to finish with three for 23.