The Olympic boxing tournament is underway featuring the first men's bouts without headgear since 1980 in Moscow.
Britain's Galal Yafai dominated Cameroon's Simplice Fotsala in a unanimous decision victory to open the action.
"It was good to go down in history as the first bout without headguards, but it was just another fight for me," Yafai said.
It's also the first time scoring will use the traditional 10-point system. There is a boxing event every day of the Olympics.
Italian fighter Carmine Tommasone became the first professional fighter to win an Olympic bout after 112 years of amateur competition.
Tommasone is one of three traditional pros who will compete for gold medals. He's joined by Cameroon's Hassan N'Dam and Thailand's Amnat Ruenroeng.
The International Boxing Association's high-profile plan to entice prominent pros to Rio de Janeiro didn't work. The stars didn't come out to try and add some gold, silver or bronze to the green they make fighting professionally.
Tommasone defeated Mexican boxer Lindolfo Delgado via a three-round unanimous decision in a lightweight bout.
Tommasone fought roughly 14 pounds over his pro weight after qualifying in a special tournament reserved for professionals.
Moroccan boxer Hassan Saada is officially out of the Olympics.
He was arrested Friday on allegations he sexually assaulted two Brazilian housekeepers in the Olympic Village. Police said the possible attacks happened Wednesday. Under Brazilian law, suspects can be held for a long period while a case is examined.
With Saada out, Turkey's Mehmet Nadir Una was declared a walkover winner and advanced to the round of 16 in the light heavyweight division.
Nico Hernandez won a unanimous decision over two-time Olympian Manuel Cappai. Hernandez looked sharp over the final two rounds against the Italian fighter in the opening session of the boxing tournament.
There are only six men on the boxing team and just one serious medal contender. The American men failed to win any Olympic medals for the first time in London.
Hernandez is from Wichita, Kansas, and his parents were set to leave the U.S. for the first time to watch their son.
American fans starting "U-S-A!" chanted were quickly drowned out by boos by fans who again seemed to enjoy rooting against the United States. Lightweight Carlos Balderas also heard boos when he became the first American in the boxing tournament to win his bout earlier in the day.