RIO DE JANEIRO — Deep in the second day of the decathlon, a rare hint of vulnerability from Ashton Eaton gave his rivals an unlikely glimmer of hope.

The man known as the world’s greatest all-round athlete had failed twice at a low height in the pole vault and faced a final attempt in the scorching afternoon sun at the Olympic Stadium on Thursday. His wife, Brianne Theisen-Eaton, who had already won Olympic heptathlon bronze for Canada, was looking on anxiously, doubting there could be any crack in his composure.

An unlikely chance for his rivals to finally beat him?

Forget it.

“That was the moment I thought ... your whole life has been about this,” Eaton said. “Getting ready for this. What are you going to do?”

His third attempt at 4.90 meters was perfection, and he went on to clear 5.20 and to make sure his invincibility in the 10-event competition would continue.

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If there was any further doubt about his mettle, the javelin throw did away with that, too. After a bad first throw, he crept closer to the top mark of main challenger Kevin Mayer of France and made sure the concluding 1,500 meters was only a race for the Olympic record.

With a final thrust across the line he tied the mark of 8,893 points the Czech Roman Sebrle had set at the 2004 Athens Games. One second either way would have made the difference.

He went into the competition aiming to beat his world record, but expecting such a feat each time he competes just shows the mindset of the 28-year-old American. His inability to produce a record on demand showed he is merely human.

Grimacing in pain for the lactic acid building in his legs, Eaton immediately went over to congratulate silver medalist Mayer.

“To be so close to a world-record holder, a man so gentle and humble, that already was exceptional,” Mayer said.

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Eaton remained unbeaten in major competitions since he was left with silver at the 2011 world championships. And a second straight Olympic title puts him among only a few of the greats. Asked whether that put him in exclusive company, he said: “The decathlon is exclusive company.”

And even if it’s true that the decathlon requires traits of self-centered focus, Eaton remains a U.S. Olympic team member first and foremost.

So when Kerron Clement was running the 400-meter hurdles final as the decathletes were competing in the discus throw, he couldn’t hold himself back when his roommate took gold and crumbled to the ground in exhaustion.

He ran over onto the track and put his hands on Clement’s back with heartfelt congratulations. “I felt somebody,” Clement said. “I was on the ground, exhausted.”

For long, it has been Eaton’s knack to be better in giving than receiving.

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Sometimes it can turn against him.

During the heptathlon competition, he sat in the stands with a Canadian cap, showing support for his wife. Some accused him of being un-American and were critical.

It stung. After all, this is a proud athlete who already had the national anthem play at five major global championships.

“Have I not represented USA well? Yet u demand more. Ur respect is hard earned,” Eaton tweeted, defending himself and his wife. “I support the country that produced my wife.”

When a Canadian, Damian Warner took the lead in the opening 100 on Wednesday, Eaton immediately responded by taking the lead on the second event. He never looked back.

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On Friday, the U.S. anthem will be played in Eaton’s honor again during the victory ceremony.

Still, seeing his wife get bronze was just as special.

“It was unbelievable. I was glad I got to watch every second of it, and she is a massive inspiration to me,” he said. “For us to have done this together is ...” and then he sighed, lost for words.