Great Britain’s women can win no better than a bronze medal in the team pursuit after a calamitous ride in qualifying on the second day of the UCI Track Cycling World Championships in London.
With just over 1km of the 4km distance remaining, Ciara Horne and Joanna Rowsell Shand lost contact with Laura Trott and Elinor Barker and eventually crossed the line several seconds behind their team-mates in 4min 21.054sec, almost five seconds down on quickest team United States in fifth place.
It means Britain can no longer qualify for the gold-medal final and must be one of the quickest teams in the field when they face China in the last eight on Friday to stand any chance of reaching the bronze-medal final.
Should they fail to win a medal, it will be the first time they have done so at a World Championships in the history of the event.
British Cycling head coach Iain Dyer said: "It's a disappointing performance. There's no way of dressing that any differently. It's fair to say it wasn't as cohesive [a performance] as it could have been.
"What we've got to do is turn it around and get ourselves back into medal contention tomorrow. We can still ride for bronze."
Britain had been second in the time sheets behind the Americans when their problems began with about 1.5km to go.
Both Horne and Rowsell Shand were unable to complete their full turns on the front of the quartet and when Horne subsequently lost the wheel of Barker in front of her, an unbridgeable gap quickly opened up between the two halves of the British team.
Horne was starting in the absence of Katie Archibald, who was ruled out of the championships with knee and arm injuries suffered in a motorbike crash in December.
Dyer added: "Naturally, we would have liked Katie to have been at the races. She's a strong rider in the team and she's nearly back to her best.
"We have known for a long time we wouldn't have Katie in London for the World Championships. We tried to give it our best shot here and it didn't pan out."
Reigning world champions and world record-holders Australia also struggled badly in qualifying, finishing only two-tenths of a second ahead of Britain and more than four and a half seconds down on the United States.
The Americans, on the other hand, produced a remarkable performance to set the second fastest time in history, 4min 16.180sec.