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."
Gemma Rowland has had a 'whirlwind' start to her international career with Wales. Despite losing to France, she is confident Wales Women can bounce back and claim a rare Triple Crown against Ireland on Sunday, as WRU TV's Graeme Gillespie discovers.
The Wales teams return home for the Irish leg of their Six Nations campaigns in this week's Principality Welsh Rugby Union Podcast. We speak to Wales attack coach Rob Howley and defence coach Shaun Edwards, as well as flanker Dan Lydiate and full back Leigh Halfpenny. We hear from Wales Women's back rower Sian Williams and Wales U20 forwards coach Chris Horsman and flanker Ollie Griffiths.
Wales look to build on victory in Paris in this week's Principality Welsh Rugby Union Podcast. We hear from coach Warren Gatland and captain Sam Warburton, as well as Wales Women's coach Rhys Edwards. We also hear from Wales U20 duo Dan Jones and Joe Davies, along with Wales U18s.
We look ahead to the French tests in this week's Principality Welsh Rugby Union Podcast. We look ahead to Wales France with Warren Gatland, Sam Warburton, Scott Baldwin, Rhys Webb and Jonathan Davies. Wales Women are the only team in red still unbeaten in this Six Nations, we speak to captain Rachel Taylor. Wales U20 are looking bounce back from defeat in Scotland, we hear from coach Jason Strange, captain Rory Thornton and front rower Dillon Lewis.
Warren Gatland and Sam Warburton look ahead to this week's crunch RBS 6 Nations tie against France, where the Wales skipper in particular is keen to make his mark, as Paris has proved a bleak place for him in the past.
Wales can still win the Six Nations title in Rome, full coverage in this week's Principality Welsh Rugby Union Podcast. We hear from coach warren Gatland, captain Sam Warburton, as well as front row pair Scott Baldwin and Aaron Jarvis, while Alun Wyn Jones reflects on the victory over Ireland. Wales U20 defence coach Richard Hodges and outside half Jarrod Evans look ahead to Italy, while Wales Women's team manager Ben Rose looks at how their success has helped the game in Wales.