Argentina ended a disappointing World Cup campaign on a high as they ran in seven tries to hammer the United States 47-17 with a sometimes scintillating display in their final Pool C game on Wednesday.
The Pumas, whose qualification hopes were ended by defeats at the hands of France and England, picked a young team and the newcomers took their chance to play with confidence and ambition that left the Americans clutching at shadows in Kumagaya.
There were two tries each for Joaquin Tuculet and man-of-the-match centre Juan Cruz Mallia, while recalled five-eighth Nicholas Sanchez, Jeronimo De La Fuente and Gonzalo Bertranou also scored to secure their ninth win in nine meetings with the USA.
They finish third in the pool with 11 points from their wins over Tonga and the Americans, but that represented a considerable step backwards for the 2015 semi-finalists, especially on the back of such an impressive Super Rugby campaign by the Jaguares.
"[The youngsters] were incredible, we really expected that from them and they really delivered. Obviously, we're out of the World Cup, but with those guys, the future is looking good for Argentina," said coach Mario Ledesma.
The USA, who have now managed only three wins in their 26 World Cup games, will hope to end with a fourth from their final game against Tonga but will have to dramatically improve their defence after missing almost 50 tackles.
Argentina were on top from the start, and Mallia set up the first try when he cut through a ragged American defensive line to feed Sanchez on his shoulder after 19 minutes.
Sanchez then set up the second as his short kick took a horrible bounce to wrong-foot Mike Te'o and give Tuculet an unexpected second, followed soon after by his own second and the team's third.
The Americans got on the scoreboard at the end of the half when five-eighth AJ
MacGinty sent a grubber kick into the corner for captain Blaine Scully to scamper on to and touch down.
Bautista Delguy had the crowd on their feet at the start of the second half with an outrageous run from behind his own line and through half a dozen defenders all the way to the halfway line.
He was unable to complete, but the next score was only minutes away as Mallia, again untouched, got the fourth, and soon after, and identical fifth after a quick lineout caught the Americans napping.
It was then Jeronimo De La Fuente's turn to run in unharried.
The Americans kept going and were rewarded when Paul Lasike showed great strength to smash his way over for their second try.
Bertranou then became the latest to benefit from more great work by Mallia, but the USA had the final word with Scully's second.
Argentina 47 (Juan Cruz Mallia 2, Joaquin Tuculet 2, Gonzalo Bertranou, Jeronimo de la Fuente, Nicolas Sanchez tries Sanchez 5, Benjamin Urdapilleta cons) USA 17 (Blaine Scully 2, Paul Lasike tries AJ MacGinty con)
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