with ~ in the rearview mirror
With his opening-day defeat in the rearview mirror, Hakuho, who is seeking his seventh consecutive title, dismantled his opponent's attack as he broke free of Tochinoshin's grasp and got both hands around the mawashi before waltzing his winless opponent out.
http://mainichi.jp/english/english/newsselect/news/20150512p2g00m0sp082000c.html
今日取り上げるのは、with his opening-day defeat in the rearview mirrorという表現です。UG先生も、過去にput… in the rearview mirrorという表現を取り上げておられました。
この場合は、「一敗した初日のことは忘れて，気持ちを切り替えて」という意味になると思います。(Kawada）
