Great Britain finished the opening day of the Track Cycling World Championships in Minsk without a gold medal as the men's team pursuit squad had to settle for silver behind arch-rivals Australia.
After Becky James and Vicky Williamson won women's team sprint bronze and Kian Emadi finished fourth in the men's one-kilometre time-trial, Ed Clancy, Steven Burke, Andy Tennant and Sam Harrison failed to defend the world title Britain won in Melbourne last April.
The quartet, who qualified second fastest, trailed Australia throughout the 16-lap final and finished in four minutes 00.967 seconds, to their rivals' 3mins 56.751secs.
Glenn O'Shea dropped out of the Australian line-up entering the final kilometre, but Alex Edmondson, Michael Hepburn and Alex Morgan had enough to hold off Britain and claim gold. Clancy, Burke, Geraint Thomas and Peter Kennaugh won London 2012 Olympic gold last August, ahead of Australia.
James and Williamson, 19 and making her senior World Championships debut, earlier won Great Britain's first medal of the championships, clocking 33.893 seconds to claim third place ahead of Australia in the bronze medal ride-off.
Olympic champions Kristina Vogel and Miriam Welte of Germany added the world title with victory in 33.053. China's Gong Jinjie and Guo Shuang, controversially denied victory at London 2012, had to settle for silver in 33.083, while Australia's Kaarle McCulloch and Stephanie Morton finished fourth in 33.898secs.
For Williamson and James the result was a major boost in the first World Championships since London 2012 and the first on the road to the 2016 Olympics in Rio de Janeiro.
Britain were represented at London 2012 by the now retired Victoria Pendleton and Jess Varnish, who was replaced by Williamson in Minsk due to a back injury. Britain qualified in third courtesy of James' second-lap acceleration and she repeated the trick in the third/fourth ride-off to make certain of a medal.
Meanwhile, in an event removed from the Olympic programme following Sir Chris Hoy's win in Athens in 2004, Emadi - making his debut senior World Championships appearance - clocked one minute 01.756 seconds to place provisional first in the men's one-kilometre time-trial with eight riders to go.
Francois Pervis, the penultimate rider to go, won in 1min 00.221secs, with Simon Van Velthooven of New Zealand second in 1.00.869 and Joachim Eilers of Germany third in 1:01.450. Emadi will now ride in the men's team sprint on day two alongside Olympic champions Philip Hindes and Jason Kenny, taking Hoy's man-three slot in the three-lap event.