Champions in 2007, Iraq had been behind twice before Adnan’s sublime set-piece secured all three points for Srečko Katanec’s relieved charges against a highly rated Vietnam side at Abu Dhabi’s Zayed Sports City Stadium.

At a competition where, so far at least, several of the region’s powerhouses have had things far from their own way, the victory saw Iraq go second in the Group D standings, behind the Islamic Republic of Iran who top the table following their 5-0 win over Yemen a day earlier.

The Samurai Blue, heading into their first major campaign under head coach Hajime Moriyasu, may be a team in transition but that isn't going to stop them from the mission of lifting the sparkling new AFC Asian Cup trophy come February 1.

Standing in Japan's way in Wednesday's opening Group F match are Turkmenistan, whose confidence has been boosted by Jordan defeating defending champions Australia, Palestine holding Syria and the Philippines giving Korea Republic a mighty test before eventually losing 1-0.

The White Wolves will be featuring in their seventh edition of the Continental showpiece and Cuper insists his players are ready to be tested in the UAE.

“Our team had good preparation leading up to the tournament, especially our centralised camps which included high-intensity trainings. We didn’t only focus on Oman but also the tournament as a whole and I’m satisfied with how everything went,” said Cuper.

“I’m not worried that we didn’t not play any friendlies before the tournament. I made that decision for a valid reason. Sometimes players can pick up unnecessary injuries, so I didn’t want to expose my players to that kind of risk.

The 26-year-old Al Gharafa favourite scored twice on a night when the three-time Asian champions were rarely troubled by opponents making their debut in the competition as a unified nation.

Iran’s impressive victory saw them assume pole position in Group D, a flying start that Taremi believes will stand his side in good stead going forward.

In a match that was dominated by Korea Republic, the Azkals displayed impressive character to keep their opponents at bay before Hwang Ui-jo’s 67th minute strike eventually sealed the East Asians the win in the Group C tie.

Both the player and Syrian team confirmed the 27-year-old would play no further part in the competition, and faces a six-month stint on the sidelines after he sustained an anterior cruciate ligament tear in the first half of Sunday's goaless draw against Palestine.

Omari, who plays his club football for Doha-based Qatar Sports Club, revealed the details of his injury via social media.

Yu Dabao scored with 12 minutes remaining to give the Chinese all three points in the Group C clash after Akhlidin Israilov had put Kyrgyz Republic ahead three minutes before the break, only for an own goal from goalkeeper Pavel Matiash to allow China to pull level.

Lippi’s team showed a marked improvement in the second half having been second-best in the opening 45 minutes and the former Juventus and Italy coach was puzzled by his team’s lacklustre display in the first half.