A late penalty by USA fly half Kimber Rozier proved the difference as Wales fell to a 7-10 defeat in their 2014 World Cup warm-up match at Pandy Park in Cross Keys.
Both sides scored one converted try apiece with winger Vanesha McGee ploughing over for USA and No 8 Sioned Harries replying in the second half for Wales.
Both sides ignored the wind and rain to play an open game of rugby with McGee and full back Akilaini Baravilala a constant threat with ball in hand for USA while Dyddgu Hywel and Laurie Harries featured regularly in counter attacks for Wales.
The teams were deadlocked until the 39th minute when USA ran the ball right and McGee dived over to score a well-executed try despite the best efforts of Harries and Hywel in defence. Rozier landed an excellent conversion to give the Americans a hard fought 7-0 lead at the interval.
Wales got back in to the game in the early stages of the second half through their forwards with Caryl Thomas and Catrin Edwards willing workhorses.
Wales got back on level terms in the 60th minute after holding onto possession for several phases. The ball was spread wide where Sioned Harries was lurking with intent and the speedy No 8 showed a clean pair of heels as she cut back against the grain to score under the posts. Laurie Harries added the extras to bring the scores level at 7-7.
Wales continued to attack but were guilty of coughing up possession at crucial times. USA made them pay by bursting downfield to set up Rozier for a penalty after Welsh forwards were penalised for coming in at the side of a ruck. The fly half had no trouble striking the ball between the uprights to edge her side back in front.
Wales finished the match in the ascendency but couldn't find a way through as USA held out for a gritty win.
Despite the narrow defeat, Wales Women's head coach Rhys Edwards was satisfied with his team's efforts.
"Going into the game we didn't know much about them but we knew it was going to be a tough game, especially as they are ranked in the top five teams of the world. The scoreboard doesn't really reflect that so I'm pretty pleased with the performance.
"We created some chances against one of the best teams in the world - the difference being when they get a chance they score, we don't. We take two, three, four or five times to get on the score board. We've got to show some composure and a bit of belief but we are certainly knocking on the door.
"We are improving and we showed that today. As we look ahead to the World Cup, we have another game against Ireland and there is no reason why we can't kick on from there and challenge in France."
The Women's Rugby World Cup warm-up clash between Wales and USA proved bittersweet for centre Elen Evans. Despite being one of the star performers on the day on her 50th Test appearance, USA edged home 10-7 at Cross Keys.
Wales U20 head coach Byron Hayward and back row Will Boyde believe defence will be the key when they face Ireland tomorrow in the second pool game of the Junior World Championship being held in New Zealand.
Tension was palpable as players waited to hear the announcment of the Wales touring squad of South Africa. Matthew Morgan was one of four uncapped players named in the squad after impressing in the Wales Senior Trial.
Wales Trial, Principality Premiership Awards evening and Wales U20s in this week's Principality Welsh Rugby Union Podcast. We hear from Jamie Roberts and Matthew Rees about the Wales Trial, captain Dafydd Lockyer talks about Pontypridd dominating the Principality Premiership awards, while ahead of the start of the Junior World Championships we talk to Tom Williams, Steffan Hughes, Jack Dixon and Nicky Smith.
Coaches Rob Howley and Robin McBryde today confirmed their Probables and Possibles teams to take part in Friday's Wales Senior Trial at the Liberty Stadium and both are predicting some mouth-watering head-to-heads.
Possibles coach Robin McBryde has given his team a licence to thrill in Friday's Wales Senior Trial match. He tells WRU TV's Graeme Gillespie that his side will be determined to ruffle a few feathers against the favourites, the Probables.
We look at the squads for the Wales trial, European finals weekend and Wales U20 on this week's Principality Welsh Rugby Union Podcast. We hear from Warren Gatland and Rob Howley on the trial, full back Hallam Amos on his summer hopes, Wales legend Ieuan Evans welcomes European rugby finals weekend to Cardiff and Wales U20 hooker Ethan Lewis looks ahead to the Junior World Championships.
Wales Under 20 head coach Byron Hayward says last night's 31-19 win over Scotland was a crucial building block as the Junior World Cup rapidly approaches. WRU TV's Liz Jones gets his post match reaction.
It is the end of an era in Welsh rugby as Liza Burgess ends almost 30 years involved with Wales Women, on this week's Principality Welsh Rugby Union Podcast. We also hear what back Robyn Wilkins about what made her take up rugby. Gwyn Morris talks about getting the Principality Premiership referee of the year award, while we hear from director of rugby Mark Hammett at the Blues, Ospreys coach Steve Tandy and Dragons back Hallam Amos about the new season.
Having taken part in seven World Cups as a player and coach, Liza Burgess hopes to go out in style this afternoon when Wales take on Australia in the Play-off for seventh and eighth place in the Women's Rugby World Cup in Paris.