Former England batsman Mark Butcher rescued Division Two leaders Surrey with a century as his team closed 316-9 against bottom of the table Glamorgan.
Butcher won the toss but Surrey lost Jon Batty first ball, Ali Brown third ball for four and when James Benning departed for 11 it was 98-6.
Seamer David Harrison claimed four of those wickets but Butcher then shared 152 with veteran Martin Bicknell.
Having hit 20 fours and a six, Butcher was eighth out, before rain ended play.
It was the 20th century of Butcher's career and the 40 over partnership with Bicknell was a Surrey record for the seventh-wicket against Glamorgan.
Harrison had unsettled the visitors with a hostile opening spell of 4-43 from 14 overs, the pick of the deliveries one that bounced and left Mark Ramprakash to find the edge.
Butcher fell lbw attempting to sweep former England colleague Robert Croft, before the players left the field at 1705 for bad light, after which rain descended.