David Tameilau scored his second try in the 80th minute Saturday and Ben Cima's conversion kick lifted the United States into a 27-27 draw with Argentina to capture the Americas Rugby Championship.
Both teams finished 4-0 with one drawn in the Six Nations-style event but by taking a bonus point for four tries in the concluding match, the visiting USA Eagles took the crown with 22 points in the table to 21 for 2016 champion Argentina.
Super Rugby Jaguares center Gabriel Ascarate scored a try in the 63rd minute to give Argentina a 27-15 lead.
But the Americans pulled within 27-20 on Dolan's try down the wing in the 74th minute, setting the stage for Tameilau's closing heroics after Cima had been stopped just short of the line.
Uruguay downed winless Chile 45-14 in Saturday's other match, the hosting finishing third on the table at 3-2.
Argentina's Domingo Miotti and Cima exchanged early penalty kicks before Will Magie's first Eagles try put the USA ahead and Tameilau followed with a try off a maul for a 15-3 USA edge.
Two penalty tries were awarded to Argentina, the first in the 40th minute after Mike Te'o was whistled for a deliberate knock on as the hosts pulled within 15-10 at half-time.
In the 53rd minute, the Americans surrendered a penalty try for holding up the scrum and Argentina converted for a 17-15 lead, which Miotti extended three minutes later on a penalty.