Trott in third
Laura Trott's defence of her women's omnium title appeared a more distant prospect after the fourth of six disciplines on the fifth and final day of the Track Cycling World Championships in Minsk.
The 20-year-old Olympic champion was third overnight, five points adrift of London 2012 silver medallist Sarah Hammer of the United States, who consolidated her advantage with victory in the three-kilometre individual pursuit.
Hammer clocked three minutes 31.550 seconds in an event in which she won the world title on day one, with Trott's 3mins 34.761secs good enough for third.
It means with the scratch race and 500metres time-trial remaining, Hammer leads on 10 points, seven points ahead of third-placed Trott. Poland's Katarzyna Pawlowska is second on 16 points and Australia's Annette Edmondson fourth on 19.
Fresh from her maiden senior World Championships title in the women's sprint, Becky James resumed where she left off, winning her Keirin heat in supreme fashion. The 21-year-old from Abergavenny led from the front and claimed a comfortable victory to progress to the second round.
Ekaterina Gnidenko of Russia also advanced at the first time of asking by coming second to James, while the remaining riders fell into the repechage.
Vicky Williamson, who won team sprint bronze alongside James on day one, was drawn in the second heat and finished fourth to drop into the repechage. Kristina Vogel, sprint silver medallist behind James, won, with Lisandra Guerra Rodriguez second.
Trott was third in the scratch race as Belgium's Els Belmans won the penultimate event after claiming a lap. Hammer was fourth and has a 14-point total and near unassailable six-point lead over Trott entering the final discipline.
Edmondson is now third on 24 points, while Pawlowska was ninth in the scratch, falling a point behind the Australian in the tussle for bronze.
Williamson needed to finish in the top three of her repechage heat to join James in the second round. She could only finish fourth, though, as her senior World Championships debut ended.