Shortly before the British men won gold in the team sprint in an Olympic record, the quartet of Laura Trott, Katie Archibald, Elinor Barker and Joanna Rowsell-Shand, clocked four minutes, 13.260 in the qualifying round of the 4,000m event.
It surpassed the mark of Australia (4:13.683) set at last year's world championships and threw down the gauntlet to world champions the United States who were second quickest.
Australia were third-fastest qualifiers.
The U.S. team led by Sarah Hammer, and boasting a unique bike with the chain on the left-hand side rather than the usual right, had threatened to go even quicker before slowing.
Hammer, desperate to win her country's first gold in women's Olympic track cycling, was not too concerned.
"It's a race over three days. We're super-excited and we've got the out for everybody," she said.
"That's what was expected. It's going to be even faster. World record, the Olympic Games, right?"
Britain were also fastest in the men's team pursuit qualifying with Bradley Wiggins, bidding for a British record eighth Olympic medal, looking in fine fettle.
Wiggins, who won road time trial gold in 2012 weeks after winning the Tour de France, returned to the track this year and was part of the squad beaten by Australia in the world championships in London.
Wiggins, Ed Clancy, Owain Doull and Steven Burke threatened the British world record set at London 2012 as the new track proved faster than some had been suggested in the build-up.
New Zealand's team sprint silver medallist Eddie Dawkins said the fast times were not surprising.
"Any track is fast when you're putting the fastest dudes in the world on it," he said.
"The Olympics brings the best out of people and everybody steps up to a new level."
(Editing by Toby Davis/Greg Stutchbury)
