Four-time Asian Cup winners Japan sealed their place in the last 16 at the 2019 edition with a controversial 1-0 victory over Oman in Abu Dhabi.
After being pushed all the way in their opening Group F victory over Turkmenistan, Japan were again far from their best as two contentious penalty decisions proved pivotal on Sunday.
Genki Haraguchi scored the only goal after Raed Saleh was adjudged to have fouled him just before the half hour, while Yuto Nagatomo was lucky not to concede a spot-kick at the other end for handball.
Victory means Japan progress to the knockout stages, while Oman could join them as one of the best third-placed teams should Uzbekistan beat Turkmenistan and they do the same on Thursday.