DOHA, Dec. 6 (Xinhua) -- China qualified for the knock-out stage after beating Oman 2-1 in a bad-tempered soccer match at the Doha Asian Games on Wednesday.

Oman, whose only chance to qualify for the last eight was a big victory over China, gained the upper hand after opening of the match.

China's defense was in chaos at the 28th minute under pressure and was punished with a penalty after Oman midfielder Al Mukhaini Ahmed was downed by Chinese goalkeeper Wang Dalei in the box.

Ahmed converted the penalty, giving Oman a 1-0 lead.

China launched a counterattack and striker Gao Lin equalized at the 42nd minute with a beautiful header.

But the match became violent and out of control at the end of the first half. Oman midfielder Bait Doorbeen Fawzi was expelled for striking the Chinese goalkeeper in the face.

The two sides exchanged words after the whistle and another Oman player got a red card after knocking down Chen Tao.

After the interval, China gained an advantage over nine-man Oman. Chinese captain Zheng Zhi sealed the victory after scoring apenalty at 55th minute.