Olympic 2016 Medal Count: Sunday's Easy-to-View Nation Rankings and Results

Sunday is a big day out on the track at the 2016 Summer Olympics in Rio de Janeiro. There are multiple medal events scheduled for Day 9, but the one that will draw the most attention is the men's 100-meter final, where Jamaica's Usain Bolt will look to make a third gold medal in a row at this event and defend his title as the world's fastest man. 

Elsewhere, American Simone Biles will look to build upon her dominant gold medal-winning performances in the individual and team all-arounds with a strong showing in the vault final, while tennis has its big day with gold-medal matches in men's singles, women's doubles and mixed doubles.

As the Olympics heads into its second week, the United States is pacing the field when it comes to the overall medal count, thanks to plenty of medals racked up in swimming.

Here's a look at the live medal standings and a preview of some of the medal events set for Sunday. 

It's been eight years since Usain Bolt emerged as a global superstar with his world-record-breaking run in the 100 meters at the 2008 Beijing Olympics.

Even though he's not considered the ideal size for a sprint champion, Bolt's long legs and effortless stride have allowed him to hold on to the title as world's fastest man, dominating events in the 100, 200 and relays with his Jamaican teammates. 

Bolt will have to fend off a challenge from the United States' Justin Gatlin, who posted the fastest time in the opening heat at 10.01 seconds, six-hundredths of a second better than Bolt. 

"I felt OK. It wasn't the best start. Felt kind of sluggish. It's the fact that it's the morning," said Bolt, per the Eddie Pells of the Associated Press. "I'm not used to running this early at any championship."

David J. Phillip/Associated Press

Ivory Coast's Ben Youssef Meite and Andre De Grasse both qualified for the semifinals with better times than Bolt and could challenge for a medal on Sunday, but it would an absolute shock if they outraced either Bolt or Gatlin in the final, assuming they all make it through. Jamaica's Yohan Blake is also a threat, having won silver in the 100 in London.

In gymnastics, Biles is looking to capture her third gold medal in Rio on the vault. While the vault isn't her best event—that would be the floor exercise, though some might even consider it the beam—it doesn't mean she can't be the best in the world.

One only has to watch her exceptional vault from the individual all-around, which gave the 19-year-old American the lead after one rotation.

Biles will face stiff competition from Russia's Maria Paseka, who won bronze in the vault at the 2012 Summer Games in London and took gold at the 2015 World Artistic Gymnastics Championships in Glasgow, Scotland. The 21-year-old earned a silver with Russia in the team all-around, so the vault final provides an opportunity for her to get one over on Biles. 

David Goldman/Associated Press

Challenges will also come in the form of India's Dipa Karmakar and Uzbekistan's Oksana Chusovitina, who will both be attempting the dangerous Produnova vault. Bustle's Morgan Brinlee has more on the difficult maneuver: 

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In its most basic definition, the Produnova is a front handspring off the vault table followed by roughly two and a half somersaults. While that may sound simple enough, it's incredibly risky. Gymnasts who don't gain the height needed to pull off the somersaults risk serious injury. Landing the Produnova is no easy feat and many gymnasts won't even attempt it.

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If Karmakar or Chusovitina can land the Produnova vault cleanly, the score from the high degree of difficulty could put them over the top. 

After winning the gold medal in men's singles tennis at the 2012 London Games, Andy Murray has a chance to bring home the top hardware yet again with a win over Argentina's Juan Martin Del Potro on Sunday. 

Murray thrashed Japan's Kei Nishikori 6-1, 6-4 to book a spot in the final on Saturday. He should be fresh for the match, though the same can't necessarily be said for Del Potro. The 27-year-old Argentinian upset Spain's Rafael Nadal 5-7, 6-4, 7-6 (5) in a thrilling semifinal to make sure he will improve upon the bronze medal he earned in London. Del Potro also defeated Novak Djokovic earlier in the tournament. 

Vadim Ghirda/Associated Press

While Murray's lofty position in men's tennis is secure with or without a win on Sunday, for Del Potro, a gold medal could be just the boost his flagging career needs. Winner of the 2009 U.S. Open, Del Potro has struggled with injuries in the years since, participating in only two Grand Slam events since 2013.

Once considered a rising star, Del Potro is now more of a veteran shark, capable of derailing a tournament run with his attacking play. A gold medal in Rio would be a huge prize for Del Potro, and perhaps a sign that the turbulence of the past few years are behind him.