The 35-year-old former world pole vault champion, who planned to end her career here, did so on a low note as the back injury she suffered on the eve of the Games prevented her from registering a mark in qualifying.

Taylor’s mission to retain the title he won in London 2012 became simpler two days ago when his great rival, Pedro Pablo Pichardo, had to scratch from the qualifying competition.

The 26-year-old from Uniondale, New York - whose 18.21 metres to win last year’s world title was the furthest anyone has managed other than Britain’s Jonathan Edwards, whose 1995 mark of 18.29 still stands - effectively settled matters with a season’s best of 17.86m in the first round.

His US team-mate Will Claye got closest to it, taking silver with a personal best of 17.76m, also in the first round, with Bin Dong of China also producing a personal best of 17.58m in the third round to claim bronze, injuring himself in the process and taking no further part.

Taylor admitted afterwards that he would have preferred to have competed during an evening session.

“I'm a night person so jumping in the morning was hard," he said. 

"On the bus I said 'leave it all out there'.

"I wanted it so much. 

"It came together, the stars aligned.

"I wanted the world record but it wasn't to be.

“I'll keep pushing for it - it's been there so long."

Croatia's Perkovic also gained her objective through one big effort as she registered 69.21m in the third round, jumping up and down on the spot and flexing her arms in triumph and perhaps relief. 

All five of her other throws were fouls. 

It didn’t matter.

France’s Melina Robert-Michon took silver with a national record of 66.73m, ahead of Cuba’s world champion Denia Caballero, who earned bronze with 65.34m, but never looked capable on the day of approaching her personal best of 70.65m.

Usain Bolt, already with three Olympic 100m titles in his possession, got his campaign for a second defence of the 200m title underway, slowing down over the final 50 metres of his heat to register an easy win in a conservative 20.28.

“I was nervous because the 200m is my favourite event and I didn't want to go out,” he said.

"I've recovered from the 100m.

 I'm tired now, but happy to be through. 

"I'm looking forward to tomorrow’s semi-finals."

On the question of whether he will seek to beat his world record of 19.19sec tomorrow, he responsed: “I will have enough rest and enough energy to definitely try.

“But we will see tomorrow how it goes."

Bolt’s perennial rival Justin Gatlin won his heat easily in 20.24 and former world and Olympic 400m champion LaShawn Merritt, who won bronze here two nights ago and who leads this year’s world 200m listings with 19.74, also progressed as he won his heat in 20.15.

Elsewhere Almaz Ayana, who produced a world record of 29:17.45 in the first session of athletics here on Friday, was fastest qualifier in the event she knows best, the 5000m, clocking 15:04.35 ahead of fellow Ethiopian Senbere Teferi who ran 15:17.43 and Kenya’s world 10,000m champion and silver medallist here, Vivian Cheruyiot, who clocked 15:17.74.

Despite her reported stomach problems, defending women’s pole vault champion Jennifer Suhr was among the top qualifiers with 5.60m along with Cuba’s world champion Yarisley Silva.

Brianna Rollins, the 2013 100m hurdles champion, topped the qualifying with 12.54 ahead of US team-mate Kristi Castlin, but sadly Sweden’s 35-year-old world indoor record holder Susanna Kallur, making her championship return this year after six injury-ravaged years, missed the cut by three places after running 13.04.

Charlie Grice of Britain was reinstated as a qualifier for the 1500m semi-finals after he had been bundled over mid-race by Norway’s 23-year-old European champion Filip Ingebrigtsen, who was disqualified.