A night that started with disappointment — if Ryan Lochte’s fourth place in Monday’s first Olympic swimming final can be called that — concluded with a barrage of medals for the United States swim team and not a few strange moments that generated what resembled a medley of emotions.

There was Lochte’s shock at missing the medal podium in the 200-meter freestyle, an event in which he is the reigning world champion. Then came pure delight from Missy Franklin, 17, who won her first Olympic gold medal after a hasty and unusual preparation.

She claimed the first of three backstroke medals — Matt Grevers and Nick Thoman got the gold and silver in the men’s 100 — for the United States.

Momentary embarrassment touched U.S. breaststroker Breeja Larson, who accidentally jumped into the pool before the 100 breaststroke final, a race won by a 15-year-old from Lithuania. That speedy youngster left reigning world champion Rebecca Soni surprised — and wearing a silver medal for the second straight Olympic Games.

“This is just an incredibly fast Olympics,” said Grevers, who won his race in 52.16, an Olympic record. “To win a medal, it’s not an easy thing to do.”

All things considered, the United States punched out a great night. There were two golds and two silvers to balance out Lochte’s bruised ego. “Not so happy about that swim tonight,” Lochte said via Twitter after the race.

The competition actually began when Franklin swam in the semifinals of the 200 freestyle at just past 7:30 p.m. Hoping to conserve energy for the 100 backstroke final, which took place about 14 minutes later, Franklin posted the eighth-best time, barely qualifying for Tuesday’s final.

But she did. Then she got out of the water and hurried — not to the distant practice pool, but to the diving well that sits next to the competition pool. There, she did a short warm-down swim. Or was it a warm-up swim? Whatever it was, it was quick.

“There’s no words that can fully describe what she was going through, what she pulled off, and how it affected all of our team,” said Tyler Clary, who along with Michael Phelps advanced to the 200 butterfly Tuesday in a late semifinal.

Franklin not only made it to the starting blocks on time, but she also came back to upset Australia’s Emily Seebohm, who had posted the fastest time in the event this year. A quarter of a second behind at the turn, Franklin touched the wall in 58.33. Seebohm clocked a 58.68. Joy registered on Franklin’s face.

“I saw that board, I saw the number 1,” Franklin said. “It doesn’t seem real. I’ve dreamed about it so often. You still feel like you’re dreaming.”

For Lochte, whose event was sandwiched between Franklin’s pair, the evening played out like a nightmare. Last week, he pronounced himself ready to dominate as he had at last year’s world championships, winning five gold medals and one bronze. But after a victory in the 400 individual medley Saturday, Lochte was overtaken Sunday night on the anchor leg of the 4x100 freestyle relay. Then, Monday night, he got left behind in the 200 free.

It wasn’t close. France’s Yannick Agnel, who had chased Lochte down in the relay, crushed the field, winning in 1:43.14. Korea’s Park Tae-Hwan finished in 1:44.93 and China’s Sun Yang, 1:44.93. Lochte finished in 1:45.04 – 0.60 seconds slower than he went at last year’s world championships.

“I guess I took it out a little too fast,” Lochte said. “I’ll live and learn.”

Grevers took Lochte’s failure personally.

“It’s tough to see a teammate and a friend maybe not do as well as he wanted,” Grevers said. “It’s not like [I wanted] revenge or anything, but I got a little bit fired up.”

That was apparent. Grevers, who stands 6 feet 8 and weighs more than 200 pounds, overtook Frenchman Camile LaCourt in the home stretch of the 100 back after trailing at the turn.

Grevers, who won the silver medal at the 2008 Summer Games, looked immediately to the scoreboard, but admitted it took him a good 10 seconds to realize Thoman had gotten the silver in 52.92. He figured that out only when a joyous Thoman swam over and embraced him.

“He was just grinning like an idiot,” Thoman said. “So I had to go over and give him a big hug.”

That kicked off, said Grevers, “a whole new celebration. It felt even better to share that moment.”

Celebration soon turned into confusion. In the next race, Larson, who had posted the third-fastest time of the year in the event, jumped early into the water, anticipating the starting signal before it sounded.

“My heart sank at first, thinking, ‘Did I just get [disqualified]?” Larson said. “I kind of pretended it didn’t happen. . . . Nobody saw that.”

As it turned out, Larson was not disqualified. She was allowed to return to the blocks, but was distracted when the race finally began. Soni was distracted, too — by the swimmer Ruta Meilutyte, the Lithuanian who emerged like a firework at this meet. Meilutyte led throughout and got the gold in 1:05.47.

Soni touched the wall in 1:05.55. Larson, meantime, finished sixth in 1:06.96 — more than a second slower than she finished at the U.S. trials. She, however, greeted reporters with a shrug and a smile as Soni confessed to a bit of disappointment.

“You have to make some mistakes, before you get them all right,” Larson said. “You appreciate the good things when bad things happen. You don’t appreciate your toes until you stub one.”