As Labour's Don Touhig swept to an expected comfortable victory with a 13,097 majority in the South Wales seat vacated by Neil Kinnock, Plaid Cymru's Jocelyn Davies delighted nationalists by emerging as runner-up with 2,933 - 12.7 per cent of the vote.
But the verdict from the valleys on Tory candidate Robert Buckland - his share of the vote slumped from 14.8 per cent in 1992 to just 3.9 - is a clear rebuff to Mr Major in the wake of the Tories' slight improvement in recent opinion polls.
Yesterday's appalling weather exacted a heavy price on voter turnout - just 45.26 per cent compared with 81.5 at the general election. But Mr Touhig surprised even Labour activists by none the less securing a healthly 69.17 per cent of the vote, not far behind the 74.3 per cent bequeathed by Mr Kinnock when he resigned to become EC transport commissioner.
Mrs Davies, 35, a well-known local politician, schools inspector and the only woman candidate fought a hard campaign and Plaid Cymru will interpret her relative success as a powerful vote for Welsh devolution.
Mr Blair has pledged to create a Welsh Assembly, but details about its scope and powers are still out for consultation. But Labour concentrated its by-election campaign on jobs, health and quality of life. The Liberal Democrats are strong supporters of devolution and and regional government, but their candidate John Bushell stayed in third place with 2,448 votes, 10.6 per cent.
Full results: Don Touhig (Lab) 16,030; Jocelyn Davies (PC) 2,933; John Bushell (LD) 2,448; Robert Buckland (C) 913; David Sutch (Loony) 506; Hugh Moelwyn Hughes (UK Independence) 289; Timothy Rees (Nat Law) 47. Lab majority 13,097