Fly-half Ian Madigan converted five penalties to lead Ireland to a 15-12 victory over a determined United States on Saturday.
The USA proved to be stubborn opposition in Houston as they kept the scoreline close throughout.
Interim head coach Les Kiss was in charge of Ireland for the first time and had to make do without those players currently touring Australia with the British and Irish Lions.
A narrow Test match ultimately decided by the boot - Madigan outscored Saracens back Chris Wyles by five penalties to four.
Ireland took the lead early when Madigan slotted a penalty in the ninth minute after the USA's scrum collapsed.
The Eagles' Brian Doyle needed some tending to after a ruck in the 13th minute, but Samu Manoa took revenge and got the crowd on its feet when he lined up an Ireland ball-carrier with a big tackle moments later.
The physicality of the Eagles turned into penalty trouble once again in the 18th minute with hands in the ruck, and Madigan took full advantage with another penalty to give Ireland a 6-0 lead.
Although the Eagles couldn't find the try line, sustained pressure on a tiring Irish defence drew a penalty, which Wyles converted to trim the deficit to 6-3.
Madigan's third penalty of the night in the 31st minute again stretched the visitors' lead, and also sprung Manoa into action.
The Northampton Saint used his big frame and speed to get through a few tackles at midfield to get the Eagles into attacking territory and drew another penalty. Wyles kicked for the posts and the Eagles found themselves again down by three.
Ireland's chances were few, but a kick across the field in the 35th minute stretched the Eagles defense.
Takudzwa Ngwenya stepped up to take away the scoring chance and forced Ireland to knock on. The Eagles committed one last penalty before the half-time whistle and paid the price, as Madigan kicked his fourth penalty of the half for a 12-6 lead at the break.
Things got worse for the hosts in the second half when captain Todd Clever was judged to have made a high tackle and sent to the sin bin. Madigan duly stepped up to kick the penalty and extend Ireland's lead to 15-6.
Consecutive penalties from Wyles pulled the USA back to 15-12, but even with Clever back in action they couldn't get any closer.
Despite the disappointment, the United States can be encouraged by the result as they prepare to host Tonga on Saturday in the Pacific Nations Cup in Los Angeles. On the same day, Ireland will play a Test against Canada in Toronto.
Pens: Wyles 4
Pens: Madigan 5
United States: 15 Chris Wyles, 14 Luke Hume, 13 Seamus Kelly, 12 Andrew Suniula, 11 Takudzwa Ngwenya, 10 Toby L'Estrange, 9 Mike Petri, 8 Todd Clever (c), 7 Scott LaValla, 6 Samu Manoa, 5 Louis Stanfill, 4 Brian Doyle, 3 Eric Fry, 2 Chris Biller, 1 Shawn Pittman.
Replacements: 16 Zach Fenoglio, 17 Nick Wallace, 18 Phil Thiel, 19 Peter Dahl, 20 John Quill, 21 Robbie Shaw, 22 James Paterson, 23 Adam Siddall.
Ireland: 15 Robbie Henshaw, 14 Fergus McFadden, 13 Darren Cave, 12 Stuart Olding, 11 Simon Zebo, 10 Ian Madigan, 9 Isaac Boss, 8 Peter O'Mahony (c), 7 Chris Henry, 6 Iain Henderson, 5 Devin Toner, 4 Mike McCarthy, 3 Mike Ross, 2 Richardt Strauss, 1 David Kilcoyne.
Replacements: 16 Mike Sherry, 17 Jamie Hagan, 18 Tom Court, 19 Dan Tuohy, 20 Tommy O'Donnell, 21 Paul Marshall, 22 Paddy Jackson, 23 Felix Jones.
Referee: Francisco Pastrana (Argentina)
Assistant referees: Bryan Arciero (Canada), Chris Assmus (Canada)
Assessor:: Clayton Thomas