Coach Kiatisuk Senamuang saw his Thailand side miss a penalty that could have put pressure on Japan. Thananuwat Srirasant/Getty Images

Thailand were left to rue a penalty miss that could have changed the game as Yuya Kubo hit a late double to help Japan cruise to a 4-0 victory at the AFC U23 Championship in Qatar.

Despite a confident start from Thailand, Japan soon took control of the Group B match and took the lead through Musashi Suzuki. Shinya Yajima added a second at the start of the second half before Thitiphan Puangchan missed a penalty that could have brought the War Elephants back into the game. Kubo's brace then rubbed salt into Thailand's wounds.

Thailand suffered an injury blow as striker Chenrop Samphaodi -- who starred in the 1-1 draw against Saudi Arabia on Wednesday -- was not fit enough to start.

But head coach Kiatisuk Senamuang altered his formation and Buriram United wing back Narubadin Weerawatnodom started in his place -- the only change from the first XI against the Saudis.

In contrast, Japan made six changes from the side who edged past North Korea 1-0 in an unimpressive opening performance.

Thailand made an excellent start and won their first corner on three minutes after a Narubadin burst down the right. Pakorn Prempak's deep corner was headed wide by Adison Promrak.

But, after seeing Thailand dominate possession for the first five minutes, Japan showed their quality when a superb volley from Yuta Tokoyawa was saved by Somporn Yos.

Soon after, a fine through ball from Yajima found Takuma Asano, who hit the post with a powerful strike from a narrow angle on the left. And at the end of an intense period of dominance from Japan, a scramble in the box ended with Tokoyawa heading onto the bar with the goal at his mercy.

The Thais recovered after weathering a mini storm and the game settled and goalmouth action died down. But after 27 minutes, the Samurai Blue suddenly came to life again when Wataru Endo sent a fine pass over the top to Suzuki. The striker controlled the ball with his head and struck a superb volley past Somporn to open the scoring.

The Japanese had assumed control of the game after a testing start and the War Elephants struggled to make an impact. Skipper Chanathip Songkrasin tried to prompt his teammates into action but their opponents closed them down quickly and effectively, preventing any clear-cut chances.

Thailand brought on Chenrop for Pakorn at halftime in an attempt to change the course of game but, just three minutes into the second half, Japan added a second goal. Riki Harakawa collected a cut-back on the left wing, drove forward and chipped the ball to the far post, where Yajima out jumped Tanaboon Kesarat to head home.

Chanathip attempted to lead a fightback when he held off his markers and fired a shot wide from long range.

And in the 53rd minute, the Thais won a penalty when Japanese defender Masashi Kamekawa barged into Thitiphan from behind. Thitiphan took the penalty himself but slipped in the run-up, mis-hit the ball and hit the bar.

Thailand kept up the pressure and Chenrop soon found space in the box and fired off an inventive volley, which forced Masatoshi Kushibiki into a save, low at his left-hand post.

Kushibiki and Chenrop clashed again when the Japanese keeper was forced to come and meet a long ball, with Chenrop closing in. The two collided but both fell, and the Thai forward was unable to take advantage.

The Thais were enjoying their best spell of the game but, having failed to score the penalty, it was a long way back from two goals down.

In the 71st minute, Peerapat Notechaiya made good ground on the left and sent in a fine cross but Narubadin's header went well wide. And Japan put the game beyond Thailand in the 74th minute when substitute Kubo beat the offside trap and lifted the ball over Somporn, whose touch only helped the ball into the net.

To compound Thailand's misery, Kubo's run down the left was ended by a Tanaboon foul in the 83rd minute and Kubo got up to slot home the penalty.

The game ended with Japan well on top and Thailand now have to pick themselves up, knowing that nothing less than victory over North Korea on Tuesday will give them a chance of reaching the quarterfinals.