Hampshire lost 22-17 at home to Gwent as their unbeaten record went up in smoke.
But Hampshire remain second in the table and have a game in hand on the leaders.
Maxine Cadwallader (Gosport) put Hampshire 1-0 up but they then lost the ladies’ B match 5-1.
The men’s second-string trailed 4-0 before the momentum swung and Tony Hutchinson (Gosport), Lee Ward, Mick Street, Dennis Simpson, debutant Dean Jones (Portsmouth), Bob Crawley (Cowplain) and Dave Harper (Gosport) sealed it.
Gwent took the last set to boast a 10-8 lead overnight.
Pennie Lewis and Sue Thompson (both Gosport) started the ladies’ A team off well but Gwent won the clash 4-2.
Hampshire needed at least nine sets from the men’s A match to secure an overall victory, and Sam Rooney, Andy Mitchell, Phil Harty (Gosport) and Steve Musson (Portchester) put them 4-0 up.
Gwent halved their deficit before Kevin Murrell made it 5-2.
The Welsh team pulled another set back but Gary Stafford (Fareham) and Arron Monk bagged wins.
However, Gwent took the last two sets to restrict Hampshire to a 7-5 victory which was not quite enough.