Australia broke an Olympic swimming event world record for the first time since 2009 at the Commonwealth Games on Thursday, putting the U.S. on notice one month before the Pan Pacific Championships.
The Australian 4x100m freestyle relay quartet of Bronte Campbell, Melanie Schlanger, Emma McKeon and Cate Campbell clocked 3 minutes, 30.98 seconds to win gold in Glasgow.
It easily the beat the previous world record of 3:31.72 set by the Netherlands at the 2009 World Championships, the peak of the high-tech swimsuit era.
Cate Campbell, the reigning World champion in the 100m free, is the best of the Aussie bunch. U.S. fans may remember her winning bronze in the 50m free at the 2008 Olympics, when she was 16 years old and swimming in the lane next to 41-year-old Dara Torres, who won silver.
Campbell came back with Schlanger and two others to win the 4x100m free relay at the 2012 Olympics, ahead of the Netherlands and the U.S., which had Missy Franklin leading off.
However, Franklin and the U.S. beat Australia by .12 of a second at the 2013 World Championships. The Americans clocked 3:32.31, the fastest ever by a U.S. quartet, but also 1.33 seconds slower than what the Aussies just posted Thursday.
The Aussies and the U.S. will duel again at the Pan Pacific Championships in Gold Coast, Australia.
In terms of the Olympics, the 4x100m free is likely to be one of several events Franklin swims. Last year, Franklin became the first woman to win six gold medals at a single World Championships.
The record for most golds won by a woman at a single Olympics is also six, by East German swimmer Kristin Otto in 1988. If the Aussies are this fast now, they might just play a role in keeping Franklin from matching Olympic history in Rio de Janeiro.