Reigning champions England suffered a 25-0 defeat by Ireland in the women's Six Nations, their first loss in the competition since 2009.
Alison Miller scored three tries for Ireland in Ashbourne, near Dublin, with a fourth by Niamh Briggs.
England - who have won the title for the past seven years and the Grand Slam for the past three - are fielding a second-string squad in the tournament.
England started the defence of their title with a 76-0 win over Scotland.
England have rested 17 front-line players for the Six Nations in order to concentrate on the Sevens World Cup in June.
And head coach Gary Street made eight changes, one positional, from the side that thumped Scotland last week.
Miller scored two tries in opposite corners to give Ireland a 13-0 lead and the Munster wing completed her hat-trick before half-time to finish the game as a contest.
Briggs added a fourth try shortly after the restart and England were unable to breach the Irish try-line despite a late surge.
"We're obviously massively disappointed with the result, but Ireland were excellent, they dominated us," said Street.
"They upped their game from last week and we just couldn't deal with it. We'll look at the video of this one and then move on and put all of our focus on the France game."
England face France at Twickenham in a fortnight's time, while Ireland, who narrowly beat Wales last week, travel to Scotland.
England team: Kay Wilson (Bristol), Francesca Matthews (Richmond), Abigail Chamberlain (Richmond), Amber Reed (Bristol), Sally Tuson (Bristol); Ceri Large (Worcester), La Toya Mason (Wasps); Rochelle Clark (Worcester), Victoria Fleetwood (Lichfield), Sophie Hemming (Bristol), Rowena Burnfield (Richmond), Tamara Taylor (Lichfield), Joanna McGilchrist (Wasps), Hannah Gallagher (Saracens) Sarah Hunter (capt.) (Lichfield)
Replacements: Emma Croker (Richmond - for Fleetwood, 53), Laura Keates (Worcester - for Hemming, 53, Roz Crowley (Lichfield - for Clark, 42), Rebecca Essex (Richmond - for Burnfield, 48), Harriet Millar-Mills (Lichfield - for McGilchrist, 58), Georgina Gulliver (Lichfield - or Mason, 68), Lauren Cattell (Saracens - for Wilson, 48), Fiona Pocock (Richmond - for Matthews, 58).