Ireland started the brighter of the two teams, and opened the scoring through outside-half Sarah Jane Belton after twenty minutes played. Belton began to dominate the first half as she continued to keep Wales pinned in their own half but the Welsh defence remained firm as they began to get the upper hand at set-piece and the first half ended 7-0 to Ireland.
With potential World Cup qualification riding on the outcome, Wales dominated in the second half from start to finish with the Welsh fly-half Awen Thomas orchestrating proceedings as Ireland had done in the first half. 18-year-old full back Elen Evans scored the first of her two tries to level the scores.
Wales were now dominant in the scrum and inspirational captain Melissa Berry crossed the line for her first international try. Ex-Welsh footballer Manon Williams replicated Berry's first international try with one of her own, as the curtain came down on an impressive second half showing by Wales.
Wales now face England in the semi final on Wednesday evening with France playing Scotland in the second semi final.