After winning 13 in a row, the Yankees lose the second game of a doubleheader to Detroit, 8 – 6. They now trail Cleveland by half a game.

On July 18, 1954 — After winning 13 in a row, the Yankees lose the second game of a doubleheader to Detroit, 8 – 6. They now trail Cleveland by half a game.

Source:
Baseball Reference July 18