Clinical Iran reach Asian Cup quarters to face VAR-assisted Japan

Ritsu Doan scored from the spot in Japan's 1-0 win over Vietnam as the video assistant referee system marked its tournament debut with a bang, the Blue Samurai marching on to face top-ranked Iran in the last four.

Iran continued on their quest to end a barren run at the Asian Cup dating back 43 years with Mehdi Taremi, Sardar Azmoun and Karim Ansarifard all on target in Abu Dhabi.

Carlos Queiroz's side drew first blood after 18 minutes of an embarrassingly one-sided quarter-final when Azmoun squared for Taremi to sweep home after some calamitous Chinese defending.

Iran's second was almost a carbon copy -- much to the chagrin of China coach Marcello Lippi, who stood staring in horror.

This time Liu Yiming misjudged a hopeful punt down-field, allowing Azmoun to nip in and round goalkeeper Yan Junling to score his fourth of the tournament.

China's best chance came after just six minutes when Hao Junmin wriggled free, only for Iran defender Ramin Rezaeian to slide in with a superb goal-line clearance to deny Wu Lei a tap-in.

Iran could have been out of sight by half-time as Azmoun -- known by Team Melli fans as the "Iranian Messi" -- twice went close and Taremi missed an open goal.

Ehsan Hajsafi forced a sharp save from Yan on the hour mark before Ansarifard raced clear to add a third in stoppage time.

Sleeping giants

It was another dominant performance from Iran, who also equalled South Korea's record of keeping clean sheets in their first five games at a single Asian Cup.

Asia's highest-ranking side, seeking to capture the title for the first time since completing a hat-tricks of wins in 1976, are co-favourites with South Korea to go all the way.

China finished runners-up in 1984 and 2004 but the sleeping giants of Asian football failed to seriously trouble Iran as their challenge ended in a whimper.

Japan won the last of their record four Asian Cups in 2011 and have hardly set the world alight at this tournament.

But they had too much quality for Vietnam in Dubai, Doan converting the spot kick on 57 minutes after a penalty awarded by VAR technology.

Japan captain Maya Yoshida also had a headed goal chalked off for hand-ball on review as VAR made an eventful Asian Cup debut.

Vietnam went close with a long-range effort from Nguyen Phong Hong Duy but the Southeast Asian champions lacked the creativity to break down Japan.

"It doesn't matter how you win -- the important thing is to get through," said Japan coach Hajime Moriyasu.

"We knew Vietnam would be obdurate opponents but the players kept their focus and we move on."

On Friday, holders Australia face hosts UAE, while South Korea -- runners-up to the Socceroos four years ago -- take on Qatar.