Iraq claimed one of the all-time great Asian Cup shocks on Friday when they defeated one of the tournament favourites in Japan and qualified for the knockout stages in Qatar. A first-half double from Aymen Hussein earned Iraq a 2-1 victory – their first over the Japanese in 42 years – in front of jubilant fans at the Education City Stadium. Iraq won their first game at the tournament 3-1 against Indonesia and their latest victory took them top of Group D with six points, three clear of Japan in second place. They face Vietnam in their final group game on Wednesday. "Today is a great day for Iraqi people but for us it's just a win. We have six points, but the players must now think of Vietnam and they need to rest,” Iraq manager Jesus Casas told reporters. “I'm very proud of my players. All Iraqi players should be proud … The perfect match is impossible, but we were close to the perfect match I wanted.” Roared on by thousands of Iraqi supporters in the stadium, Iraq opened the scoring inside five minutes when Japan goalkeeper Zion Suzuki failed to deal with a cross, parrying the ball straight to Hussein who headed it into the top corner. Iraq, who are ranked 63 in the world to Japan's 17, made 2-0 in first-half injury-time when Ahmed Al Hajjaj skipped past his marker and floated in a cross that was headed home from point-blank range by Hussein. A goal from Liverpool midfielder Wataru Endo in the third minute of second-half injury time ensured a nervy finish but Japan could not find the goal that would prevent them losing an Asian Cup group-stage game for the first time in 26 matches. Hajime Moriyasu's side – who beat Vietnam 4-2 in their opening game and went into the tournament on the back of a 10-game winning streak – could need a result in their final match against Indonesia to reach the knockout stages. For the second game in a row, Japan conceded twice in the opening 45 minutes but in the Vietnam game, they at least went in at the break 3-2 in front. But the Samurai Blue were left with a mountain to climb this time round thanks to Hussein's headed brace. They brought on Takehiro Tomiyasu at halt-time for the Arsenal defender's first appearance of the tournament and thought they had won a penalty in the 56th minute when Rebin Solaka was adjudged to have tripped Takuma Asano. But a VAR check revealed the tackle to have been a clean one, and Ritsu Doan was also out of luck when he curled a free kick over the bar less than 10 minutes later. Substitute Mohanad Ali almost gave Iraq a third goal midway through the second half but his shot flew agonisingly wide of the post. Endo gave Japan hope when he pulled one back deep in injury time but it was too little, too late. “We prepared the same way as we did for Vietnam but unfortunately we found ourselves in a difficult position, especially early on. The crowd and atmosphere made us feel like we were playing an away game,” Moriyasu said. “The second goal hit us hard, we must learn from our mistakes. The players fought hard and I must accept responsibility for the loss. “We analysed before the game and knew how Iraq would play at the start, they did play very aggressive. Unfortunately we couldn't handle it, I know we need to do more.”