By Martyn Herman

LONDON (Reuters) - Fresh out of college, Christa Harmotto made the bold decision to continue her volleyball education halfway around the world in China and three years later it is paying handsome dividends.

On Wednesday, the 25-year-old middle blocker was part of the United States team that produced a powerful performance to beat China 3-0 and seal a quarter-final spot at the Olympics.

Harmotto's position on court brings her face to face with the full fury of the opposition spiker but more often than not she appeared to second guess the Chinese attack during an electrifying contest at the cavernous Earls Court.

It was no accident, the Penn State graduate said, explaining how she had learned a new style of volleyball while playing professionally in the city of Guangzhou in 2009.

"It was a different culture and a different style of game," Harmotto told Reuters.

"They play very fast so it was important for me in my block (and to help) the growth of the game and for me to see some different offenses before I joined the national team.

"I was under a great coach and surrounded by great players who demanded the best out of you. We were able to make plays that I could learn from and pick up on."

She was in good company as the Guangzhou team at the time contained several members of the Chinese women's team that won the Olympic gold medal in Athens in 2004.

Now playing in Modena, Italy, Harmotto said she has a healthy respect for Chinese volleyball and was not surprised by the incredible resilience they displayed in saving six match points before finally succumbing.

"Every time you step on the floor against China they definitely exploit some things that as far as our defense we are not used to, they have a fast offence, they hit off one foot, the setter does a great job disguising her sets," she said.

"It helped me a lot as a young player right out of college. They are technically sound. The former Olympians were in the team and it was fun to watch, they took the technical skills to a whole new level.

"They keep coming at you and it's fun to play them."

With three wins from three matches, the U.S. team are looking the most impressive of the 12 nations involved in the tournament, but Harmotto is not looking any further than their next Pool B preliminary match against Serbia on Friday.

"We're not even thinking about medals yet," she said.

(Reporting by Martyn Herman; editing by Ken Ferris)