Plaid Cymru has won the Caerphilly Senedd by-election, taking the seat from Labour for the first time in its history.
The vote was called following the death of Labour MS Hefin David earlier this year.
Plaid Cymru's candidate, former councillor Lindsay Whittle, received 15,961 votes (47%), ahead of Llyr Powell of Reform UK on 12,113 votes (36%). Labour’s Richard Tunnicliffe came third with 3,713 votes (11%).
Mr Whittle paid tribute to Hefin David following his win, saying he will be a "hard act to follow".
"I will never fill his shoes but I assure you I will walk the same path that he did."
He also urged Cardiff and Westminster to listen saying he wants a "better deal" for every corner of Wales.
"The big parties need to sit up and take notice. We are at the dawn of a new beginning”.
First Minister Eluned Morgan said the outcome was “disappointing” and that Labour would “listen to what voters have said.”
The result marks a significant end to Labour's dominance in Caerphilly.