The Japanese striker had only been on the Olympic stadium pitch for five minutes on Wednesday when he was freed to unleash a superb left-foot 74th minute strike to earn City a 1-1 draw at FC Seoul, ensuring they extended their unbeaten streak in the competition to four matches.
It also cemented their push towards the the knockout stages as they moved onto 10 points from six matches to lie fourth in the ACL East group table. The first eight in the league will advance to the last-16 in March.
Seoul had taken the lead 10 minutes before halftime with a neat first-time finish from former Manchester United and England star Jesse Lingard, who was playing his last match after a couple of years with the K League side.
The 32-year-old Lingard was an early menace for City, opening up their defence after just 12 minutes only for Lee Seung-mo to have his shot blocked by Argentine defender German Ferreyra.
But Lingard eventually beat Patrick Beach with an assured low first-time finish into the bottom corner after being fed by an inch-perfect cross from Choi Jun.
After the break Elbasan Rashani thumped one wide for City and they were also denied by some last-ditch desperate defending to thwart Nathaniel Atkinson just as he was about to knock home a Rashani pass.
Seoul's Brazilian star Anderson unleash a shot that clipped Beach's right-hand post as the hosts went for the jugular, but instead it was City who took the initiative, Kavian Rahmani sliding the ball across to Kanamori, with the 31-year-old slamming a terrific shot home from 20 yards into the bottom corner.
As Seoul pushed for the equaliser, Beach then made a key play in the final minute, hurling himself to his right to stop Ryu Jae-moon's goal-bound strike sealing the points.
Elsewhere, Japan's Sanfrecce Hiroshima moved up to third, behind compatriots Vissel Kobe and Machida Zelvia on 11 points after a 1-0 win over Shanghai Shenhua.
