Dublin - Ireland's second-string overpowered an ultimately outclassed United States 57-14 in Dublin on Saturday to end a brilliant year on a high.
Victory meant Joe Schmidt's reigning Six Nations Grand Slam champions had lost just the once in 12 Tests in 2018, an 18-9 defeat by Australia in Brisbane in June in the first of a three-match series.
Ireland coach Schmidt made 14 changes to the starting side that enjoyed a 16-9 win over his native New Zealand, the reigning world champions a week earlier, with centre Garry Ringrose the only player to keep his place.
"There were a couple of new combinations out there," said Ringrose. "We had to stick to our guns and reacting to conceding a try or two was a really good learning curve.
"There are still the same set of standards for everyone in the group, whether it was four weeks ago when we started this, right to the end.
"It was about upholding those standards right to the finish and making it a successful autumn," he added.
Saturday saw Munster wing Andrew Conway run in a hat-trick of tries, with Ireland scoring eight in all, although the Eagles were still in touch at just 24-14 down at the break through a try from Joe Taufete'e and a penalty try.
But Ireland, now one of the favourites for next year's World Cup in Japan, scored 33 unanswered points in a second half which saw Conway complete his treble and Tadhg Beirne, Stuart McCloskey, Quinn Roux and John Ryan also score tries.