RIO DE JANEIRO (AP) — In the midst of arguably their finest team performance in a quadrennium, a familiar nemesis provided the U.S. men's gymnastics team with a reminder that nothing comes easily.

Especially on pommel horse. Especially at the Olympics.

While having Chris Brooks and Sam Mikulak go spinning off pommels removed some of the sparkle of an occasionally spectacular Saturday during Olympic preliminaries, it also offered a reality check. As solid as the score of 270.405 points was — second only to two-time defending champion China — the Americans know it can be better during Monday's team finals.

"We just want to keep building momentum," Mikulak said. "I think that's what today was, getting comfortable on the equipment and making a little bit of a statement. Hopefully that statement will carry over and we can carry that momentum to Monday."

Four years ago in London, the Americans dominated qualifying only to slide to fifth with a medal on the line, a fall kickstarted by a forgettable set on pommels. China, which slogged to sixth in prelims, rebounded all the way to the top of the podium.

It's a painful memory that remains fresh for the five men on Team USA, all of whom were involved on the 2012 team in some capacity. This group, they insist, is not that group. They're older. Wiser. And not so caught up in their own hype.

"We were just so pumped up about everything we might have just believed in ourselves that we might have already proven ourselves," Mikulak said. "This time we all know that's not what we're going to do. ... What happened today doesn't matter on Monday."

Russia, Japan, Britain, Brazil, Ukraine and Germany all advanced to the eight-team final, though the sometimes giddy atmosphere — punctuated by host Brazil's euphoric breakthrough in front of a raucous home crowd during the opening session — was tempered by sobering reminders of the sport's ever present danger.

French gymnast Samir Ait Said broke his left leg while trying to land a vault, the crack of the bone shattering upon impact with the mat echoing throughout the arena and the shocking images of Said holding it in his hands instantly going viral.

"It is catastrophic," French teammate Cyril Tommasone said.

Andreas Toba's right knee buckled during his floor routine. While the German managed to compete on pommels, he watched the rest of qualifying in sweat pants with his right leg ramrod straight in a brace, his Olympics over.

"I cried like a little kid," Toba said. "The injury on my knee is big, but the emotional injury is way bigger."

Japan's missteps were far less painful but nearly as startling. Nine months ago after ending China's long run at the top by surging to gold at the world championships, the Japanese looked a bit overcome by the stage at Rio Olympic Arena.

Even typically poised and ever elegant defending Olympic champion Kohei Uchimura wasn't immune to the pressure.

Looking for a gold medal to bookend the one he captured in London, he went sailing off the high bar — an event where he is the reigning world champion — and smacked onto the ground in shock. The miscue means he'll miss the event final. It also cost him the top qualifying score in the all-around. Uchimura's score of 90.498 was second to Ukraine's Oleg Verniaiev, one of the rare times Uchimura hasn't found himself looking down at the rest of the field.

The scores will be reset in the individual all-around next Wednesday, though Uchimura is more concerned about getting his team mentally prepared for Monday night.

"We try to perform like the world championships," Uchimura said. "But we know this is the Olympic Games and this makes us stressed out."

The stress didn't get to China, which downplayed Japan's rise at worlds and promised to be ready by Rio. The Chinese posted the top scores on parallel bars and still rings, their three near flawless sets on rings in the final rotation giving them just enough to edge the Americans.

China delivering in the clutch is hardly new. It is new in Brazil, which made the team final for the first time, fueled by an arena that roared with every stuck landing.

The highlight came during three-time Olympic veteran Diego Hypolito's floor exercise. After falling in the 2008 floor final and failing to make the event final in 2012 after a similar mistake, tears streamed down the 30-year-old Brazilian's face after posting a 15.5, good enough for a spot in the floor final later in the games. Yet the tears were not for his score as much for his country.

"This was important for Brazil, it was about the team," Hypolito said. "I've been to three Olympics. This is something we've thought about for a long time. To perform like this, it's a dream."