New Zealand's Valerie Adams, the defending champion, has had to settle for a silver medal in the Olympic shot put.
Her great rival Nadzeya Ostapchuk of Belarus won gold on Monday night with a dominant series of throws, claiming the title with a best distance of 21.36 metres.
Adams's best was 20.7. She would have had to have thrown a personal best to beat Ostapchuk.
Evgeniia Kolodko of Russia won the bronze medal.
Adams says she is very disappointed, as she really wanted to defend her title.
"I left my heart out there trying, and that's all I could do."
She says she is the strongest she has ever been in her career and can't complain.
"We try, we train, and tonight was Ostapchuk's night and I cannot control that - I can only control what my performances are."
Adams says she was beaten by a better person, but is very happy with the silver.
"I have to be happy, you know - we got a medal for New Zealand and I'm proud to have done that for New Zealand."
One of Adams's oldest supporters, former Olympic shot-putter Les Mills, says she should still be proud of her performance.
Mr Mills told Morning Report it was just a case of Adams not being the best on the day.
"She perhaps just lacked that little spark of fire that makes the difference between winning and losing and Ostapchuk found it.
"Ostapchuk performed marvellously well. Valerie performed well, and threw a long way - but that's how competition goes, you win some you lose some."
Effect of startlist error unclear
Earlier Mr Mills said it was unclear whether being left off the startlist initially had hindered Adams' performance.
"Did it leave her hanging for a day, worrying about it, and did that knock the edge off her sort of explosive finish to a throw?
"I don't know. I would have thought she'd have put that behind her and it was just a competition where she didn't quite fire."
With the completion of the women's shot put, New Zealand remains 14th on the medal table with three gold, one silver and four bronze.
Van Dalen progresses
The other New Zealander in action at the track and field on Monday, Lucy Van Dalen, has made it through to the semi-finals of the women's 1500 metres.
The 23-year-old finished eighth in her heat, which was not in itself good enough to put her directly into the next round, but her time of 4:07.04 took her through as one of the fastest losers.
Van Dalen was in the leading bunch until midway through the final lap when she stumbled after colliding with one of her competitors.
The fastest qualifier was Ethiopia's Abeba Aregawi, the winner of Van Dalen's heat, who posted a time of 4:04.55.
The semi-finals will be raced on Wednesday.
More track and field news
In other athletics action, American Jennifer Suhr went one better than four years ago, winning the pole vault and denying Yelena Isinbayeva her third successive title. The Russian world record holder finished third.
Kirani James of Grenada, 19, won the 400 metre title, in a race noteable for the total absence of Americans, who failed to make the final for the first time ever. The Untied States had won the last seven Olympic titles.
World champion Yuliya Zaripova of Russia won the women's 3,000 metre steeplechase and Felix Sanchez of the Dominican Republic won the 400 hurdles, eight years after winning in Athens.