Ireland coach Adam Griggs says the shock 8-7 defeat by Spain in the opening World Cup qualifier is "hugely disappointing".
Patricia Garcia's penalty put the Spanish in front early in the game but it was quickly followed by a converted try from Beibhinn Parsons.
Ireland led 7-3 at the break with a tight and error-strewn game decided by an Lea Ducher try on 71 minutes.
"We just didn't turn up to play - it's hugely disappointing," said Griggs.
"We were probably outplayed in a lot of facets of the game by Spain. We left a lot of chances out there," he told RTE.
"Around the breakdown especially I thought we struggled a bit to get that quick ball. When we did get that quick ball we weren't accurate enough to really punish them.
Major setback
It is a huge blow to Ireland's hopes of progressing from the qualifiers in Parma, with only the winner of the four-team tournament progressing to the finals while the runner-ups will enter the final qualification tournament.
Just one place separates the sides in the rankings, but Ireland were firm favourites to make a winning start in the Parma sunshine.
Spain showed they would be no pushovers by winning two penalties after dominating the early scrums - Garcia hit the woodwork with her first attempt but made no mistake second time around on six minutes.
Ireland hit back in style two minutes later as Parsons collected a high pass from Stacey Flood before sprinting down the line and over for a try.
Flood added the extras but after a promising opening, the game became a scrappy affair littered with infringements and mistakes from both sides.
Ireland went close to capitalising on a yellow card for Spanish centre Amalia Argudo when Cliodhna Moloney crashed over three minutes before the break but the ball was adjudged to have been held up after a television match official (TMO) check.
The Irish got to grips with Spain in the scrum as they made a strong start to the second half and it looked like it was going to be awarded when Amee-Leigh Murphy Crowe darted through and touched down.
But the TMO came to Spain's rescue after a knock-on in the build-up was spotted and it proved to be a decisive moment as Ireland would not add to their tally.
Spain rarely threatened in the second half until the latter stages but they made the most of their foray forward, although only after Ireland's Sam Monaghan was yellow-carded on her debut, just 14 minutes after coming on.
The ball was swung wide to the left and Ducher drove through a gap to score the winning try with Gargia failing to convert.
Ireland were presented with a last-minute chance to win the game with a long-range penalty but Enya Breen's kick fell short and seconds later Spain were celebrating a shock win.
Ireland will take on Six Nations rivals Italy on 19 September before playing Scotland, the lowest-ranked team of the four, in their final qualifier on 25 September.
Ireland: E Considine; AL Murphy Crowe, L Mulhall, S Naoupu, B Parsons; S Flood, K Dane; L Peat, C Moloney, L Djougang, A McDermott, N Fryday, D Wall, C Griffin, B Hogan,
Replacements: N Jones, L Feely, L Lyons, S Monaghan, E McMahon, E Lane, E Breen, L Delany.