The Swiss athlete, Sabine Fischer, has only managed ninth place in her 1500m race at the international Nikaia athletics meeting in Nice.
Fischer ended the race on 4:11.05, well over four seconds off the leader, Romania's Violeta Szekely, who finished on 4:06.55.
Szekely, who had to be content with a silver medal in the same race at the Sydney Olympics last year, beat off strong competition from second-placed American Regina Jacobs, who clocked up a time of 4:06.69.
Olympic gold medallist Nouria Benida-Merah from Algeria, meanwhile, could only manage fourth place in Nice.
Fischer, Switzerland's only competing athlete at Monday night's meeting, finished well off her personal best time of the season of 4:05.60 and nearly three seconds off her similar ninth-placed performance in Sydney.
"Somehow it didn't quite go right for me," she admitted, "and I had to spend too much time running in the second and third lanes."
Fischer's disappointing finish well behind the leaders is a blow to the Swiss star's preparations for the World Athletics Championships in Edmonton, Canada next month.
But the 28-year-old remained resolutely optimistic in defeat, saying she was already looking forward to the next meeting.
"I'm looking ahead and the next time it will go much better," she said after the race.
The international headlines of the meeting were made when American sprinter Marion Jones cruised home to win the 100m in 11.25 seconds.
Justyna Bak of Poland caused the biggest upset of the night when she shattered the world record in the women's 3000m steeplechase. She covered the distance in 9:25.31, slashing nearly 15 seconds off the previous record of 9:40.20 set last year by Romania's Cristina Iloc-Casandra.
swissinfo with agencies