5 athletes we met in Rio who will dominate in Tokyo 2020

Heading into Rio 2016, most of the talk centered around Usain Bolt and Michael Phelps in their Olympic swansongs.

The legends certainly didn't disappoint, capturing a combined eight gold medals during the games and cementing their legacy as the two greatest Olympians of all time.

While Bolt and Phelps are riding off into the Olympic sunset, Rio 2016 also introduced us to a group of athletes who could dominate the landscape for years to come.

To qualify for this list, the athlete must have been making their Olympic debut at Rio 2016, and be young enough to realistically be in the running for a spot at Tokyo 2020. This eliminates such athletes as swimming legend Katie Ledecky, who participated at London 2012 before owning the latest Olympics.

Here's five athletes we met in Rio who will dominate in four years time at Tokyo 2022.

Andre De Grasse, Canada

The sprinting world was familiar with the 21-year-old Canadian entering Rio, but De Grasse introduced himself to the rest of the world by challenging the unbeatable Usain Bolt in the 100 and 200m. The budding bromance between the two Puma-sponsored athletes set social media ablaze. After capturing a silver and bronze in the events, De Grasse has been declared by many as the favorite for Tokyo in four years. For a Canadian kid who ran his first 100m just five years ago in basketball shorts and converse shoes, the sky is the limit.

Simone Biles, USA

Newsflash ... Simone Biles is really, really good at gymnastics. Despite having never competed in an Olympics, the diminutive American was already declared by many in the sport to be the best gymnast of all-time. Biles did nothing to alter that opinion, dominating her first Games by capturing four gold medals and one bronze. She will certainly be the favorite in Tokyo, and has a real chance at matching Larisa Latynina's nine gold medals as the most in women's gymnastics history.

Wayde van Niekerk, South Africa

Wayde van Niekerk came to the Olympics as the only man in history to break 44 seconds in the 400m, 20 seconds in the 200m, and 10 seconds in the 100m. He leaves Rio 2016 as the fastest man to ever run the 400m. The South African shattered the world record in the event, finishing in a blazing fast 43.03. He became the first man ever to win the 400m from lane eight in the process. At just 24 years of age, van Niekerk is poised for more sprinting glory at Tokyo 2020.

Penny Oleksiak, Canada

Prior to Rio 2016, the most famous Oleksiak in sports was Jamie of the Dallas Stars in the National Hockey League. The standout defenseman has been forced to take a backseat to his younger sister Penny after the 16-year-old's incredible performance at the Olympics. Four medals for the young Canadian, including a heart-stopping finish for the gold medal in the 100m freestyle, vaulted her to the top of the swimming world. Concert tickets to a soldout Drake show in her native Toronto were part of the spoils of her success, and she will undoubtedly be a major medal contender again at Tokyo 2020.

Monica Puig, Puerto Rico

Only the most hardcore of tennis fans had heard of Puerto Rico's Monica Puig heading into Rio 2016. The 22-year-old came to the event ranked 35th in the world, hailing from a country that had never won an Olympic gold medal. Puig not only made her way to the semis, but she blitzed all competition in her wake, not losing a set the entire trip. Most impressive on the journey was her 6-1, 6-1 dismantling of third-seeded Garbine Muguruza of Spain in the third round. The final saw a matchup with No. 2 seed Angelique Kerber of Germany. After trading 6-4 wins in the first two frames, Puig punished her opponent 6-1 to capture the gold. With many of the women's tennis stars in their 30's, the Puerto Rican could be a strong candidate to defend her crown in four years time.

All pictures courtesy of Action Images