The coronavirus has played havoc with Asian qualifying for Qatar, forcing some teams to play home games overseas and some matches staged in front of limited crowds or empty stadiums.
Japan, Asia’s highest-ranked team at No. 24 in the world, lost 1-0 at home to 79th-ranked Oman last Thursday to end a streak of eight consecutive wins in World Cup qualifying games.
The home team dominated proceedings and came close to breaking the deadlock, but Dick Advocaat's side defended stoutly.
Vietnam's occasional attacks mostly faltered before reaching the opposition box and South Korea keeper Jo Hyeon-woo was barely tested by a couple of tame long-range strikes.
South Korea coach Shin Tae-yong hailed the unfancied Asians' momentous 2-0 World Cup victory over holders Germany.
Calls of 'Out' and 'goodbye' rang out from the German fan zone as the weight of the 2-0 loss to South Korea sunk in.
The Germans needed to win by two clear goals in their final group F match at Kazan stadium to advance to the last 16.
South Korea made history with their astonishing run to the 2002 World Cup semi-finals but the current crop of players have struggled to hit those heights.
The South Korean gave arguably his finest display for the Spurs shirt as they emphatically ended a four-match winless streak.
Tottenham Hotspur clinched top spot in Champions League Group H after their 2-1 comeback win at Borussia Dortmund.
Tottenham joins north London rival Arsenal and Manchester City in a strong semifinal lineup that will be completed after Chelsea hosts Manchester United on Monday.