On the evening of March 7, Beijing time, the final round of the U20 Asian Cup, a divine script appeared in Group B, Vietnam went from the first in the group to the whistle out, Japan or repeat the tragedy.
In the first two rounds of the group stage, Vietnam won 1-0 Australia and Qatar 2-1 respectively, winning two consecutive games and holding the top spot in the group. In the final round against Iran, Vietnam can qualify as the first in the group as long as they draw it.
However, Iran lost 3-2 to Australia after taking all three points from Qatar, and both Iran and Australia had three points in hand after both rounds.
Because the order of the ranking rules is from mutual record, mutual goal difference to mutual goal score, so as long as Vietnam loses to Iran in the final round, and Australia defeats Qatar, if the three teams have the same score, Vietnam will definitely be out. In the case of Australia's final round win, Vietnam will lose 2 goals or more to Iran on net goal difference and will be out due to mutual goal difference, even if Vietnam loses 0-1 due to low number of goals. The only way Vietnam loses is when it scores at least 2 goals against Iran and can only lose 1 goal.
In the end, the two results of the final round of Group B, Australia 9-1 Qatar, Vietnam 1-3 Iran, in the end Iran, Australia and Vietnam have 6 points, but Iran's mutual goal difference is +1, Australia is 0 and Vietnam is -1, so Iran and Australia are first in the group and second in the group, and Vietnam is out in third place in the group.
The situation in Group D where the Chinese team is located is very similar to Group B. China, like Australia, scored three points in the second round after losing in the first round; Japan, like Vietnam, started with two consecutive wins to hold the top spot in the group, while Saudi Arabia, like Iran, won the first round but lost in the second round.
Japan could repeat the Vietnam tragedy, and if China beats Kyrgyzstan in the final round and Japan loses by two goals to Saudi Arabia, the group will also have three teams with six points, while Japan will be out on a mutual goal difference. As long as Saudi Arabia outperforms Japan by no more than 3 goals, China can even qualify as the first in the group.