一人勝ち

ひとりがち【一人勝ち】

～する sweep the board; beat everybody else (hands down); be the sole [overwhelming] winner.

●麻雀でひとり勝ちする sweep the board [be the overwhelming winner] at mah-jongg.

●この業界では S 社がひとり勝ちの状況だ. S. Corporation has swept the board [is far ahead of any of its competitors] in this industry.