Twelve gold medals will be awarded Saturday and 21 sports will be contested as the action gets underway.
There’s plenty of action on the road, in the water and in the ring as stars from cycling, rowing, gymnastics, boxing and basketball all showcase their skills.
Here are five highlights from the first full day of sporting endeavor:
Cycling
The hilly nature of the route will make it hard — though not impossible — for the sprint specialists so the medal places could go to the strongest climbers. The field will be relieved to see that the world champion, Slovakian Peter Sagan, has opted out of the road race and will compete in the mountain bike competition instead.
Some of the favorites for gold include Julian Alaphilippe (France), Vincenzo Nibali (Italy), Alejandro Valverde (Spain) and Dutch cyclists Tom Dumoulin, Wout Poels and Bauke Mollema. But watch out for a surprise. There is always a chance that another courageous rider could escape the pack, risk all on the technical sections of the descent and race home to Olympic glory on the beach.
Swimming
Three gold medals will be won in the pool. Both the men’s and women’s 400-meter individual medley will be decided Saturday along with the men’s 400m freestyle competition. The 2012 Olympic champion, China’s Sun Yang, will be defending his title in the freestyle but will face stiff opposition from Mack Horton (Australia) and American Connor Jaeger.
In the women’s medley, Hungarian Katinka Hosszu will start as favorite but will be challenged by Britain’s Hannah Miley, Spain’s Mireia Belmonte and American Elizabeth Beisel.
Heats also start in the women’s 100m butterfly, men’s 100m breaststroke and the women’s 4x100m team relay race.
Rowing
Last year, scores of dead fish appeared in the Rodrigo de Freitas lagoon, where the Olympic rowing and canoe sprint events will take place.
Bhokanal has certainly qualified the hard way. He lives in a one-room mud hut in Talegaon Rohi village, in India’s Maharashtra state, with no running water, no television and no refrigerator.
He grew up in a drought-prone region where monsoon rains were erratic, and only started rowing when he joined the army in 2011.
He says a medal is a long shot but perhaps Saturday could perhaps be his day of glory.
Basketball
The U.S. has dominated Olympic basketball in both the men’s and women’s competitions, and both teams again start as favorites.
The men have only been beaten to gold four times since 1936 — the last time in 2004 when Argentina took top spot — and the women have won gold in the last five Olympic Games.
Host Brazil takes on second-ranked Australia in the women’s tournament. France, ranked fourth, plays Turkey.
Rugby
Rugby returns to the Olympic schedule for the first time since 1924 — this time in the seven-a-side version of the game — and the host nation is in action in the first pool matches with the women’s team taking on the British.
Both the men’s and women’s competitions feature 12 teams, with the latter opening proceedings Saturday in the temporary Deodoro Stadium — which will also host parts of the pentathlon event. The men’s tournament begins Tuesday.