Mitoma and Endo on target as Japan put seven past China
Brighton winger Mitoma, who has missed a chunk of this year with injury, was making his first appearance for Japan since the Asian Cup in January.
He announced his return in emphatic style in front of more than 50,000 fans in Saitama, scoring with a first-half header after Liverpool's Endo had given Japan the lead.
Takumi Minamino added two more goals after the break to put Japan on cruise control against a China side looking to qualify for their first World Cup since 2002.
Junya Ito, who was also playing for Japan for the first time since the Asian Cup, scored another before late goals from Daizen Maeda and Takefusa Kubo capped a dominant performance from Hajime Moriyasu's side.
Skipper Endo said the win "wasn't easy" despite the one-sided scoreline.
"We came onto the pitch with positive energy," he said.
"We got the first goal from a set piece and then we played our own football and the goals kept coming. We got the three points and it was a great game."
It was a night to forget for China, who squeezed into the third qualifying round thanks to a superior head-to-head record over Thailand.
"Japan are very strong. They are the top team in Asia and it's not just Asia -- they are a world-class team," said China's Croatian coach Branko Ivankovic.
"We will work together and see if there is anything we can learn from this game," he added.
Japan and China have also been drawn with Australia, Saudi Arabia, Bahrain and Indonesia in a tricky-looking Group C.
The top two are guaranteed a place at the World Cup, with the third and fourth-placed sides going into a further round of qualifying.
Japan play Bahrain away on Tuesday while China face Saudi Arabia at home the same day.
'Relief' for Mitoma
Endo found himself completely unmarked to head in the home side's opener from a corner.
Japan doubled their lead on the stroke of half-time when Mitoma nodded home Ritsu Doan's cross at the back post in injury time.
It was the 27-year-old Mitoma's first goal for his country in more than a year, and he said he was "relieved" to get on the scoresheet.
"The home support was overwhelming and that allowed us to play well from the first whistle," said Mitoma.
"Playing against Bahrain away will be tough and I hope we can repeat this kind of performance."
Minamino got Japan off to a flying start to the second half with two goals in the space of six minutes.
Ito then marked his return to the team with Japan's fifth goal after coming on as a substitute.
The Reims winger had not featured since he left the Asian Cup squad after a Japanese magazine published allegations that he sexually assaulted two women in a hotel in Osaka last year.
Japanese prosecutors dropped charges against the player last month and he has denied any wrongdoing.