The seat has been staunchly Labour for the past century and was held for the last 18 years by Allan Rogers.
Chris Bryant won with a 47.2% gaining 23,230 with Plaid Cymru contender Leanne Woods netting 7,183.
The seismic results of the 1999 National Assembly elections - when local chemist Geraint Davies pulled off a shock win - had encouraged Plaid Cymru to spend the past few weeks turning its energies towards attempting another coup.
Labour were keen to bury the memory of former MEP Wayne David's stunning loss two years.
But they had faced Plaid Cymru - who had been canvassing hard for its prospective candidate Leanne Wood, a local councillor, on the Plaid controlled Rhondda Cynon Taff authority.
Wood caused a ripple of excitement after brandishing the Labour and Conservative parties as "British nationalist" parties - a jibe in response to the use of the term "Welsh nationalist" as a label for Plaid.
The war of words was brief and both sides settled back down to trying to win the hearts and minds of voters in the south Wales Valley constituency.
Labour believes it has learnt the lessons of 1999.
David had been a victim of a Labour backlash, which came from the grass roots, with voters dissatisfied with the party seemingly turning its back on traditional concerns.
But the result of the 1999 leadership election - brought about by Welsh Secretary Ron Davies's "Moment of madness" on Clapham Common - proved a turning point.
The people's choice - Rhodri Morgan - had lost out to "Blair's Poodle", Alun Michael, and the early months of the National Assembly's existence were overshadowed with recriminations of the selection process.
Senior party figures, including government minister Peter Hain, had pointed out the lessons that the Rhondda assembly election result held for Labour - out of touch with voters and its traditional needs.
Plaid's successful seizing of control of Rhondda Cynon Taff council was largely due to support from the Rhondda, with 20 local Plaid councillors.
But if 1999's assembly election result was a protest against the excesses of New Labour, then the outcome in the early hours of 8 June could depend very much on both parties having listened hard to local concerns.