Wales pressurised throughout the first half, capitalising on a number of Irish mistakes to keep on the front foot. Pressure was turned into more points shortly before the break, when Naomi Thomas made an outstanding break to race through the Irish defence and slip the ball to Evans to run over for an uncoverted try.
With prop Louise Horgan in the bin, Ireland capitalised on a one-player advantage, with Geri Healy ploughing over from a maul and Sarahjane Belton converting to pull back Wales' lead to only four points.
Despite continued Irish threats, it was Wales that had the final say on the board, with Evans increasing her tally by another three points.
Non Evans, Louise Rickard, Rhian Williams, Clare Flowers, Rachel Poolman, Naomi Thomas, Mel Berry, Amy Broadstock (Claire Horgan 45), Rhian Bowden (Jenny Davies 45), Louise Horgan, Liza Burgess, Rachel Brown (Claire Donovan 70, Catrina Nicholas, Kylie Wilson
Replacements: Sarah Simkin, Amy Day, Elen Evans, Philippa Tuttiett