RIO DE JANEIRO >> The Olympics began in full with the first gold medal going to an American teenager by the fearsome name of Thrasher. And there was fear and plenty of rough riding on a punishing cycling course that showed the beauty and blight of the host city.

Virginia Thrasher, a 19-year-old who once had her heart set on figure skating, captured the 10-meter air rifle Saturday. Greg Van Avermaet of Belgium won the grueling road race that left cyclists tending to scrapes, bruises and road rash.

Riders rolled off to the sound of crashing waves on Copacabana Beach on a steamy morning hours after Brazil’s high-energy opening party featuring thumping funk, sultry samba and supermodel Gizele Bundchen sauntering to the tune of “The Girl from Ipanema.”

Showcasing Rio’s famed beaches and majestic mountains, the men’s road race began under clear, sunny skies buzzing with helicopters — some carrying TV cameras, others from the military to provide security.

The brutality of the course became evident over the cobblestone sectors that rattled one cyclist off his bike, cost another his chain and forced Tour de France champion Chris Froome to change out his broken bike.

Van Avermaet out-sprinted Jakob Fuglsang and Rafal Majka on the long run to the finish at sun-splashed Copacabana Beach after Italy’s Vincenzo Nibali and Colombia’s Sergio Henao crashed while trying to navigate a corner on the final harrowing descent of the 6-hour race.

Two of the most anticipated competitions come Saturday evening in men’s basketball and swimming.

Kevin Durant, Carmelo Anthony lead the heavily favored Americans against the Chinese in hoops, although some say the real action is more than 6,000 miles away in Las Vegas, where betting on the Olympics is legal for the first time since 1998. Bookmakers installed the U.S. as 50-point favorites over the Chinese.

The men’s 400-meter individual medley is the marquee race in Saturday’s swimming program even without two of the sport’s biggest stars. Michael Phelps, the world record holder and two-time Olympic champion, dropped the race for his fifth games and defending champ Ryan Lochte didn’t qualify.

Thousands of police and soldiers were patrolling the city amid concerns about safety as athletes opened the first full day of the Olympics with table tennis, rowing, archery, water polo and fencing all taking place under a cloudless sky and warm temperatures.

Preliminary soccer games already have been played and more were on tap Saturday, along with rugby sevens, gymnastics and judo. Many of the events took place in the Olympic Park on Barra de Tijuca, a modern suburb of Rio.

Among the highlights on Day 1:

GOING FOR GOLD:

—YOUTH SERVED: Thrasher topped her spectacular spring where she won three NCAA titles and a spot on the U.S. Olympic team by upsetting China’s Li Du, a two-time gold medalist, to capture the 10-meter air rifle title. She swapped figure skating for shooting after a family hunting trip in which she killed a deer with her first shot.

—HANDBALL HOST: Host Brazil upset reigning gold medalist Norway 31-28 in the opening game of the handball tournament. Ana Paula Rodrigues led the way with 12 goals for Brazil, which has never won an Olympic handball medal. As the arena filled with passionate home fans for the early morning game, five straight goals and big saves from goalkeeper Mayssa Raquel Pessoa paved the way for victory.

—WOMEN FIRST: France won the first game of rugby at the Olympics in 92 years — and the first ever for women — beating Spain 24-7 to begin the six-day sevens tournament. Rugby sevens, the fast-pace, condensed form of the game, is the format for the sport’s return to the Olympic program for the first time since 1924, when the U.S. men won the gold medal in the 15-a-side tournament.

BAD BREAK: French gymnast Samir Ait Said’s Olympics ended when he severely injured his left leg while vaulting during team preliminaries. Said’s leg bent awkwardly as he tried to land, the sound echoing through the arena. Said writhed on the ground in agony while medical officials tended to him. He exited on a stretcher to a standing ovation.