Chris Wood's first half-century of the season ensured Hampshire escaped with a draw and left Glamorgan still looking for their second win in the LV= County Championship Division Two this term.
Rain meant only 39 overs were possible, during which time Hampshire overcame a 14-run deficit, built a lead of 108 and in the process lost two wickets. A draw was inevitable as the home side closed on 237-4 at Southampton.
The result did neither side any good since Glamorgan's 11-point haul left them still in the bottom two while Hampshire's promotion hopes receded further with their eight-point return.
In addition neither could blame the Ageas Bowl pitch which offered some help to the seam bowlers on the first day but flattened out over the course of the match.
Hampshire began the last day on 115-2 from 41 overs, still 14 behind and with Glamorgan in urgent need of early wickets before the threatened rain arrived. They did not get them.
Liam Dawson and nightwatchman Wood took root as Hampshire required 46 overs to finally clear the deficit.
There was still marginal hope for Glamorgan when Dawson was run out for 42 in the 52nd over when Hampshire led by only 40 but they quickly died when the powerful-driving Wood was joined by Neil McKenzie.
Wood and McKenzie added another 95 in 29 overs for the fourth wicket as the match limped to a tame conclusion.
The 23-year-old Wood made an aggressive 69 which included three successive fours off Graham Wagg but in Wagg's next over he mis-hooked to Michael Hogan at slip.
Wood's 69 included nine fours and came off 139 balls and at the fall of his wicket, the rain came down to force the draw. McKenzie was 35 not out when stumps were drawn.
Glamorgan captain Mark Wallace used eight bowlers in an increasingly desperate attempt to force a breakthrough and the most successful of those was Wagg who finished with 2-20.