RIO DE JANEIRO -- Four years after he first stuffed his feet into track spikes, in what's been a remarkable Olympic debut, Andre De Grasse is already one of the greatest sprinters Canada has ever seen.

But when the wiry 21-year-old from Markham, Ont., crossed the finish line second on Thursday night, a look of disappointment played across his face.

It spoke of the fearless and fierce competitor, a natural-born winner. And in the moments after he captured silver in the 200 metres, for his second medal of these Rio Games, he talked about an opportunity lost.

"I felt like I had a great shot, not sure if I just used up a little bit too much energy yesterday (in the semifinal) and didn't have anything left today," De Grasse said.

"This time a couple of years ago, I didn't think I'd be in this type of position of coming in here, Olympic debut, and coming away with two Olympic medals. And now I'm in this moment, I'm happy and grateful that I did it, but at the same time, I wanted to come away with a gold."

De Grasse crossed in 20.02 seconds, a day after he ran a Canadian record 19.80 in the semis. Jamaican superstar Usain Bolt won the gold in 19.78 to become the first in history to win three Olympic golds in the event.

De Grasse became the first Canadian to win two individual track medals in the same Olympics since 1932. He could add a third medal in Friday's 4x100 relay.

Like De Grasse, coach Stuart McMillan responded with mixed feelings, but he knew a night's sleep would bring better perspective.

"Andre is for sure going to be disappointed," said the Canadian coach. "My initial reaction from that is disappointment. But we forget, he's a 21-year-old kid, he just started track and field four years ago, he's now got two Olympic medals in his first Olympic Games.

"We'll sleep on this and we'll be ecstatic. It's an absolutely amazing achievement."

France's Christophe Lemaitre was third in 20.12 seconds.

If the Rio Olympics are De Grasse's coming out party, the Canadian has played a charming host.

On Sunday night he raced to bronze in the 100 metres, becoming the youngest Olympic medallist in track and field's marquee event since 1984.

Then in a memorable 200 semi on Wednesday, De Grasse closed on Bolt down the homestretch, trying to tire out the 29-year-old. As he pulled even with Bolt, De Grasse turned and grinned at the big Jamaican in a comical picture that launched countless Internet memes.

There were no shared smiles on Thursday, however.

Bolt, in Lane 6, got out to a great start, and was already clear of most of the field just two steps out of the blocks as De Grasse, in Lane 4, chased him around the bend.

"Andre is a really cool customer, he definitely wasn't intimidated," McMillan said. "We had a strategy to try to tire (Bolt) out. It was clear that Usain was very tired tonight, that's why we're a little frustrated, because he was there for the taking."

"Andre did not come here to get a bronze medal or a silver medal, especially in the 200, he really thought he could win."

De Grasse pressed too early in the bend, McMillan felt, and his form fell apart a bit. Bolt came off the corner in first, De Grasse in second, and there was no making up ground on the Jamaican world record-holder.

Bolt hadn't been pleased the previous night with De Grasse's tactics in the semifinals.

"I think he's used to athletes rolling over for him a little bit," McMillan said. "And there's a reason why Andre now has two Olympic medals, because he doesn't roll over, he's not intimidated at all, he wasn't going to play Usain's game."

And unlike the 100 final, where Bolt and De Grasse had walked arm in arm smiling and joking, there was no jovial post-race interaction. De Grasse took a Canadian flag, wrapped it around his shoulders, and did a victory lap alone.

"I don't need to prove anything else," Bolt said afterward. "What else can I do to prove to the world I am the greatest?"

The super-confident De Grasse is a breath of fresh air in a sport that desperately needs one. And he's a marketing dream for Puma, who signed him this past winter to a deal worth US$11.25 million. With performance bonuses, it could climb to as much as US$30 million.

It was an eye-popping deal for the rising star who just two summers ago didn't qualify for the 200-metre final at the Commonwealth Games.

But he's risen up the global sprint ranks at a dizzying pace ever since -- double gold at the NCAA championships, double gold at the Pan American Games, then bronze in the 100 and 4x100-metre relay at last summer's world championships.

De Grasse stumbled into track almost by accident when he accompanied a friend to a high school meet, and decided to race. A decent basketball player growing up -- he still has the Raptors dinosaur logo painted in the bedroom of his childhood home -- he famously won the 100 metres that afternoon wearing baggy basketball shorts and without using starting blocks.

Four years later he chased down the greatest sprinter in history. What does it all mean, a reporter asked De Grasse.

"It means I have a lot left in the tank," he said. "I think I can do some incredible things, and run some times I never thought I could run in my life before."

Earlier Thursday, Damian Warner of London, Ont., captured bronze in the decathlon with 8,666 points. He matched Dave Steen from the 1988 Seoul Games for the best-ever Canadian finish in decathlon.

Defending champion Ashton Eaton of the U.S. won gold with 8,893 points while France's Kevin Mayer took silver with 8,834 points.

Melissa Bishop of Eganville, Ont., clinched her spot in the women's 800 metre final by crossing second in her semifinal in finished second in her semifinal in one minute 59.05 seconds. Bishop was the frontrunner down the home stretch, before Poland's Joanna Jozwik kicked to pass the Canadian in 1:58.93.

Nathan Brannen of Cambridge, Ont., advanced to the finals of the men's 1,500, while Canada's men's and women's 4x100-metre relay teams both qualified for their respective finals.

Bolade Ajomale of Richmond Hill, Ont., Toronto's Aaron Brown, Calgary's Akeem Haynes and Brendon Rodney of Brampton, Ont., finished third in their heat and fourth overall in a season's best 37.89 seconds.

Canada's men's team is looking for redemption after a lane violation four years ago in London cost them a bronze medal, and left the runners in tears.

On the women's side, Farah Jacques of Gatineau, Que., Toronto's Crystal Emmanuel, Phylicia George of Markham, Ont., and Khamica Bingham of Brampton, Ont., qualified seventh in 42.70 seconds.

Alyxandria Treasure of Prince George, B.C., qualified for Saturday's high jump final with a personal-best effort of 1.93 metres.

In men's shot put, Tim Nedow of Brockville, Ont., finished 16th in qualifying and did not advance.