John Isner powered the United States to victory over Australia in the Davis Cup World Group tie with a masterful serving performance at Kooyong on Sunday.
The towering Isner served 49 aces in delivering a 6-4, 6-4, 5-7, 7-6 (7/4) victory over Australia's Bernard Tomic in two hours 15 minutes in the fourth rubber to clinch the tie with an unassailable 3-1 lead.
It puts the Americans into the quarter-finals of the men's team competition with a home tie against either Belgium or Croatia and leaves Australia in a play-off to hold on to their World Group status for next year.
"After the last couple of years it's massive for us," American captain Jim Courier said.
"This is a tough match-up on paper and it was a tough match-up in reality when we stepped on the court. So for us into the second round, it's a big deal."
The United States are the most successful nation in Davis Cup, having been crowned champions 32 times.