Day one of athletics produces shot put shock and high drama on the track

Carter conjured up a throw of 20.63 metres to snatch gold from Adams, who had been seeking to become the first woman to win three straight Olympic titles in any individual athletics event. The defending champion had to settle for silver with 20.42m. Hungary’s Anita Marton won the bronze with her final throw of 19.87 to set a new national record.

It was a special night for Carter, whose father Mike – now her coach - won silver in the shot put at the 1984 Olympics. After a 15th place in Beijing and a fifth at London 2012, she became only the second American woman after Earlene Brown in 1960 to medal in the event.

Afterwards a jubilant Carter paid tribute to her father. “He's my coach today, and he's given me everything that he knows to be the best shot putter I can be.” For his part, Mike, who went on to become a successful American football player, had this to say: “As parents, we jump for joy, are happy, but as her coach, I'm responsible for what happens when she fails. But she finally succeeded. The coach has retired for this year and the dad is now just walking around happy, with his chest stuck out.”

Reigning champion Adams was philosophical about her failed triple title tilt. “It's tough but it's sport. You have to take it on the chin. I was rushing a little but I made sure that I tried my best. At every moment I was like, ‘I need to pull something out here,' but I came up short.

“I want New Zealand to know I threw my heart out there today, I threw a season's best, so I cannot ask for more than that,” she added.

Ayana storms to epic 10,000m gold

Earlier in the day, Ethiopia’s Tirunesh Dibaba had also missed out on a hat-trick of titles when she finished third in an extraordinary women’s 10,000m, which was won by her compatriot Almaz Ayana in a new world record time.Ayana clocked 29 minutes 17.45 seconds, 14 seconds inside the 29:31.78 set by China's Wang Junxia back in 1993. Taking the silver was Kenya’s Vivian Cheruiyot.

No woman had gone under 30 minutes in the last seven years, but the first four all did in Rio, and the first 13 finishers all set personal bests.

“Getting to this point is a dream come true,” said Ayana. “I never thought that this would happen and I'm so in awe. I'm very happy to get here.”

Meanwhile, Dibaba was disappointed to miss out on her third title but still justifiably proud to make the podium for the third time in the event, an unprecedented achievment. “I did something that no one ever has done before and I'm very proud of that.”

Wang follows his heart to win 20km gold

In the men's 20km walk, Wang Zhen and Cai Zelin pulled off a Chinese one-two. It was Wang’s first major title following a bronze at London 201 and two world championship silvers.

The 24-year-old hit the front some 3,000 metres from the finish, opening up a sizeable gap on Cai and crossing the line in a time of one hour, 19.14 minutes. After a victory wave he turned to embrace Cai (1:19.26).

"I feel like I didn't have much of a plan for this race,” admitted the new Olympic champion. “I talked with my coach beforehand, but I just followed my heart.”

Australia's Dane Bird-Smith, whose father and coach David Smith competed in the event at the 1980 and 1984 Olympics, was third with a personal best time of 1:19.37 to claim a bronze medal in his first Olympics.

"Epic, eh?" said the ecstatic Bird-Smith, whose father was on hand to witness his medal-winning exploits. “I just looked at my watch; a PB as well. I just can't believe it. It feels totally unreal right now. My dad had some cracks at it, and this is my first one down, so I just can't wait to see him.” He didn’t have to wait long as Bird-Smith senior was waiting for him at the finish line.