The victory ensured Japan topped the group and sets up a quarter-final meeting with regional rivals Korea Republic at the same National Stadium in Tokyo next Thursday.
Japan were in control from the outset against the winless Swiss and were finally rewarded for their dominance on the half-hour mark as Tanaka curled a perfect free-kick from 25 metres over the wall and under the near post crossbar.
Namesake Mina Tanaka then hit a nice effort from just outside the penalty area against the base of the post, with the Swiss happy to hear the half-time whistle.
Their relief was to be short-lived, however, as Tanaka repeated her first-half effort with a carbon copy just two minutes after the break to double the lead.
It was soon 3-0 as Asuka Nishikawa was allowed too much space with a corner played to her on the edge of the penalty area and the substitute hit a good low shot home.
Finally, with six minutes remaining, Hikaru Naomoto was brought down trying to round the goalkeeper after a fine dribble into the penalty area, with the midfielder then scoring from the penalty spot with ease.
“The first goal made the difference,” said Japan coach Hiroshi Yoshida. “They were linked in defence and we were not able to attack properly. I instructed Yoko to pass the free-kick to Yokoyama, but Yoko seemed to have the confidence to score the free-kick.
"After their counter attacks, they weren’t able to score. We controlled the match and had more energy.”