The American quartet assigned to book a berth in the men's 4x100 metres freestyle relay final made the most of their moment by breaking the world record in the Olympic heats in a time of three minutes 12.23 seconds.
Nathan Adrian, Ben Wildman-Tobriner and Matt Grevers, swimming in Beijing on Sunday as the top sprinters to emerge from the US trials - Jason Lezak, Garrett Weber-Gale and Michael Phelps - were rested, combined with likely first-choice Cullen Jones to beat the previous record of 3:12.46 set by the United States in Victoria, Canada, on August 19, 2006.
Lezak, Weber-Gale and Phelps all posted 100m free times of under 48 seconds at the trials in Omaha to stake their claim to berths in the relay final, where the US expect a tough race with France and Australia.
The French boast current 100m free world record-holder Alain Bernard, while Australia have the second-fastest performer ever in the distance, Eamon Sullivan.
Both France and Australia beat the previous world record in the heats as well, despite the absence of their strongest sprinters.
The French quartet of Amaury Leveaux, Gregory Mallet, Boris Steimetz and Frederick Bousquet clocked 3:12.36, while Australians Andrew Lauterstein, Leith Brodie, Patrick Murphy and Matt Targett were third-fastest qualifiers for the final in 3:12.41.
"That was a pretty hot heat," said Murphy after the Aussies finished second in heat one to the United States.
"We knew the night time swims could bring that out of us and we went out hard, but I didn't even think we were on the world-record pace."
Bousquet's split time of 46.63 is the fastest ever, albeit with the benefit of the rolling start of a relay leg.
The explosion of fast times in the heats promised a scintillating final on Monday morning.
The 4x100m free, in which the Americans are seeking to avenge a disappointing third place behind South Africa and the Netherlands in Athens four years ago, is also one of the events Phelps needs to reach an unprecedented eight gold medals in one Games.
The French, reckoned the favorites in the event by Australian coach Alan Thompson, were expected to insert Bernard and Fabien Gilot for the final in place of Mallet and Steimetz. Bousquet was looking forward to it.
"Alain and Fabien lived the race with us from the Village. They will be eager to be here tomorrow (Monday) morning and put on their best performance."
Whatever the make-up of the US squad for the final - and coaches have some leeway under the US selection procedures - Wildman-Tobriner was under no illusion that the world record would stand for long.
"It's fun to be world record-holder overnight," he said. "Whether it's us or the French, one of us is going to be there tomorrow."