Iraq coach Jesus Casas said his team were "close to perfect" in stunning Asian Cup favorites Japan 2-1 on Friday to reach the knockout rounds, where they were joined by rivals Iran.
Aymen Hussein scored two first-half headers in front of nearly 40,000 in Doha to consign four-time champions Japan to a first Asian Cup group-stage defeat in 26 matches.
It also set Japan on a potential collision course with Son Heung-min's South Korea in the last 16, assuming they still progress.
Casas said that the first big shock of the tournament was "only one win" but hailed it as "a great day for Iraqi people".
"I think the perfect match doesn't exist," said the Spaniard.
"It's impossible to have a perfect match, but we were close to perfect."
Hussein headed Iraq -- ranked 63 in the world compared to Japan's 17 -- into the lead in the fifth minute and struck again in first-half injury time.
Iraq endured a nervous finish after Liverpool's Wataru Endo pulled one back in the third of eight minutes of injury time at the end of the game.
"All the players were concentrating on this match and we were all ready for it," said Hussein, who also scored in a 3-1 win over Indonesia.
Iraq won the Asian Cup in 2007 and are dreaming of upsetting the odds all over again.
Iran joined Iraq, Australia and hosts and holders Qatar in the last 16 but they made hard work of beating Hong Kong 1-0.
On paper the fixture was among the biggest mismatches at the tournament, with Iran ranked 21st in the world to Hong Kong's 150.
Iran, hunting a record-equalling fourth continental crown, dominated possession in front of 36,412 at the Khalifa International Stadium.
But Hong Kong -- playing at their first Asian Cup in more than 55 years -- had opportunities early on, especially when Brazil-born forward Everton Camargo blazed over from inside the box.
Iran scored what turned out to be the winner in the 24th minute when Mehdi Ghayedi slid a shot across the six-yard box and past the despairing grasp of goalkeeper Yapp Hung-fai, the ball nestling in the bottom-right corner.
