Updated

The U.S. men's gymnastics team used a pair of great all-around efforts and some early swagger to announce their medal contention at the London Games.

It didn't hurt that two of their biggest adversaries put together some mistake-laden performances.

Behind solid showings from Danell Leyva and John Orozco, the United States earned a score of 275.342 to lead all teams in Saturday's qualifier.

The American duo didn't show any nerves in their Olympic debuts, posting two of the highest all-around scores. Leyva used a team-high score on the horizontal bar for his leading 91.265 mark, while Orozco was fourth overall with a 90.597 score.

In fact, the only gymnast of the five-person team with Olympic experience, Jonathan Horton, fell on both the pommel horse and parallel bars. Samuel Mikulak also had a miscue on the horizontal bar.

Those missteps did little do rattle a squad looking to win gold for the first time since 1984.

"Can we just get the medals now," asked Horton, a veteran of the 2008 Beijing Games, when asked of repeating the team's performance in Monday's team final.

Horton had a reason for confidence after fellow contenders China and Japan struggled.

Saturday marked a slow start for the Chinese in defense of their 2008 Beijing gold medal. China found itself sixth overall in the team standings after replacement Guo Weiyang struggled.

Guo fell off the pommel horse and also struggled in earlier rotations. He failed to cleanly land one of his tumbling presses on the floor exercise and also fell forward on his dismount from the parallel bars.

The Chinese replaced Teng Haibin with Guo due to a torn muscle in his left forearm suffered by the former while training in mid-July. Teng had won gold at the 2004 Games in Athens on the pommel horse.

However, Guo's miscues, as well as one by Zhang Chenglong on the pommel horse, hampered China to a score of 269.985.

Japan, which features three-time individual all-around world champion Kohei Uchimura, finished just above China in fifth with a score of 270.503. Uchimura fell on both the horizontal bar and the pommel horse while brothers Kazuhito and Yusuke Tanaka also committed errors on the day.

Uchimura ended with the ninth-best all-around score on the night with an 89.764 mark. He won silver in the all-around four years ago and is favored to win the gold in London.

Great Britain also took advantage and finished third on the day with a score of 272.420, just .175 behind Russia. The hosts were paced by excellent performances out of Kristian Thomas (90.256) and Daniel Purvis (89.199).

"It is just awesome," said Purvis of finishing ahead of China following the first subdivision. "To be honest we were just trying to hit our routines, so to beat them is just great. But China are the world champions, they are awesome and I really think they'll pull it up a level on Monday."

Japan won silver in Beijing, with the United States finishing third.

In addition to Monday's team final, the individual all-around final is scheduled for Wednesday and the apparatus finals are set for Aug. 5-7.