World number one Australia pulverised hapless South Africa 10-0 on Wednesday to continue their impressive march towards retaining the Olympic men's field hockey gold medal.

Eli Matheson slammed a hat-trick and Jamie Dwyer and David Guest scored two goals each as the Kookaburras recorded their second successive win in Pool B at the Olympic Green Hockey stadium.

Meanwhile, Asian Games champions South Korea were given a scare by Games debutants China before romping to a 5-2 win in Pool A with Jang Jong-Hyun scoring three penalty corner goals.

China snatched a 2-0 lead by the eighth minute before the Koreans hit back to follow up their 3-1 win over the same rivals in the Asian Games final in Qatar two years ago.

Australia, who had routed Canada 6-1 in their first game, displayed their awesome strike power with five goals in each half as the 13th-ranked South Africans wilted under the onslaught.

Dwyer, whose golden goal against the Netherlands won Australia their maiden Olympic men's title in Athens four years ago, opened the floodgates with a second-minute goal.

Grant Schubert, Fergus Kavanagh and Des Abbott were the other scorers for Australia, who clash with Pakistan in their next game on Friday.

"We had a real solid game," said Matheson, whose only other hat-trick was also against South Africa.

"Maybe I should play a bit more against them. But our overall play was good, we kept the ball speed up and had a good balance with our forwards."

Guest said the way Australia had started should serve as a warning to other teams.

"If we maintain what we did, it will work for us," he said. "We did not give away too many penalty corners and now have two days to recover and see what we can work on."

Dwyer, who took the field despite suffering a hip injury against Canada, said he felt comfortable enough to play.

"I did not feel good that day because of the bruised hip, but physical therapy has done a lot of good. I am ready for more action."

South Africa, beaten 5-0 by the Netherlands in their first match, need a big turnabout if they are to avoid finishing bottom of the 12-nation competition.

"When you concede 15 goals in two matches, it's a tough battle to keep your morale up," said striker Emile Smith. "We have to take in the good and work out the bad.

"We have played the two strongest teams in our pool. So hopefully it should get easier now."

South Africa, who finished tenth in Athens, next play Britain on Friday.

The Koreans were stunned by the two early Chinese goals from Na Yubo in the sixth minute and Song Yi in the eighth, but drew level by half-time through Seo Jong-Ho and Jang.

Jang slammed in two more penalty corners soon after resumption before Kang Seong-Jung completed the tally for the Koreans.

AFP