Host South Korea hammered the United States 7-0 to open the men's football tournament at the Military World Games here Wednesday.

National team mainstay Lee Jeong-hyeop returned from a facial injury to make a surprise appearance, as South Korea netted four goals in the first half and tagged on three more in the latter half. South Korea outshot the Americans 21-6.

The Military World Games, organized by the International Military Sports Council, will take place in Mungyeong and its satellite cities in the southeastern part of the country from Oct. 2 to 11. The football competition began early with preliminary matches.

South Korea in the football tournament are being represented by Sangju Sangmu, a team made up of conscripted professionals competing in the second division K League Challenge.

Cho Dong-gun scored the first of his two goals just four minutes in, and Lee Seung-gi doubled the lead in the 20th.

With South Korea up 4-0, Lee set up Cho to make it 5-0 six minutes into the second half. In the 76th, Lee scored one for himself, and Park Gi-dong completed the rout in the next minute.

Though he didn't score, Lee Jeong-hyeop came off the bench in the 86th minute, his first appearance since suffering a compound facial fracture in a nasty collision during a league match on Aug. 26.

Lee resumed training two weeks ago and donned a protective mask in this match.

After the match, Lee said he still needs to get over a mental hump before hitting his stride.

"I still have fear (about hard contact), but it's something I have to overcome through practice," he said. "I've been out of action for so long, and it wasn't that easy to play today. But it feels much better to be out here playing than lying on a hospital bed."

Head coach Park Hang-seo initially thought about leaving Lee off the roster for the competition, but said Lee was adamant about playing in what will be his last tournament as a serviceman.

"I wanted to keep him off the field, but he really wanted to play," Park said of the player who will be discharged on Oct. 12, a day after the Military World Games end. "I will gradually increase his playing time so that he can get over his psychological barrier from the injury."

Lee played as a shadow striker, instead of his usual center forward position. He didn't get into aerial battles as often as he normally would have as the featured striker. (Yonhap)