Phelps was not the only star of the night Tuesday. Katie Ledecky of the United States and Katinka Hosszu of Hungary each won golds. For Ledecky, it was his second in Rio.
Hosszu, nicknamed the "Iron Lady," won her third gold medal. She could add another gold to her tally when she competes in her final event, the 200-meter backstroke, on Thursday and Friday.
Race for the silver
There was very little doubt the United States was going to win the women's team title in gymnastics. The question was, who is going to get silver?
It was a close race between China, Japan and Russia, with the Chinese in second going into the final rotation.
But Mao Yi, the last Chinese gymnast to perform, stumbled during her floor routine and plopped down out of bounds. She managed only a 12.633 and Russia edged the Chinese by .685 in the final result.
The United States easily won by more than eight points
, led by the incredible Simone Biles.
Still a good day for China
Despite the disappointment on the mats, China was celebrating Tuesday, winning three more gold medals. There were wins in weightlifting and at synchronized diving -- despite the unusual green pool
Diver Chen Ruolin told state-run news agency Xinhua that a few years ago, she wasn't sure she wanted to compete any more.
"Over the past two years, I have struggled a lot and it has not been easy," Chen told Xinhua. "I have even thought about quitting the sport altogether."
"Diving has really taken a toll on my body .... And now, it's like all of the pressure is gone, and I'm very relieved."
For Chen, it was the third consecutive Olympics she and her partner won the 10-meter platform synchronized diving.
Weightlifters Deng Wei and Shi Zhiyong won their divisions Tuesday.
China, with 17 medals, has the second most medals in Rio.
Another stunning Williams' loss
First it was Venus losing at singles, then she and sister Serena lost in doubles. On Tuesday, it was Serena's turn for a shocking result in singles
. She lost to world No. 20 Elina Svitolina of Ukraine.
"It's obviously disappointing but, you know, she played really well and I think the better player won today," Williams said. "It didn't work out the way I wanted to, but at least I was able to make it to Rio. That was one of my goals."
One of the siblings still have a chance to take home gold as Venus Williams will team with Rajeev Ram in mixed doubles, which begin Wednesday.
Rugby sevens loses a star
Some losses are doubly hard to take. In New Zealand's case, it was a double loss that hurt so much.
The All Blacks, a gold medal favorite in ruby sevens, lost to lightly regarded Japan 14-12
And they'll have to play the rest of the tournament without Sonny Bill Williams, a two-time World Cup winner.
But just as New Zealand was a little deflated, Japan was absolutely elated.
"It's still pretty unbelievable and I am just shocked to be honest." Japan back Lomano Lemeki said.
Media bus hit
An official Rio 2016 bus that was carrying journalists was hit Tuesday night while traveling from one Olympic Park in Deodoro to another Olympic facility in Barra da Tijuca, according to state-run news agency Agencia Brasil.
One person was injured when two windows were broken.
Accounts from passengers in the bus vary, Agencia Brasil reported, with some people saying the bus was hit by rocks and saying the damage came from gunfire.
Gold medal roundup
Equestrian Eventing Team Jumping -- France
Canoe Slalom Men's Single -- Denis Gargaud Chanut, France
Synchronized Diving Women's 10-meter Platform -- Chen Ruolin and Liu Huixia, China
Fencing Men's Epee -- Park Sang-young, South Korea
Judo Women's 63-kilogram -- Tina Trstenjak, Slovenia
Judo Men's 81-kilogram -- Khasan Khalmurzaev, Russia
Shooting Women's 22-millimeter Pistol -- Anna Korakaki, Greece
Weightlifting Women's 63-kilogram -- Deng Wei, China
Weightlifting Men's 69-kilogram -- Shi Zhiyong, China