How did Johanna win the Hunger Games?

How did Johanna win the Hunger Games? Johanna Mason is the female tribute from District 7. She won the 71st Hunger Games by pretending she was a weakling and a coward, so no one regarded her as a threat, but when only a few tributes remained, she revealed herself to be a vicious killer.

Johanna Mason is the female tribute from District 7. She won the 71st Hunger Games by pretending she was a weakling and a coward, so no one regarded her as a threat, but when only a few tributes remained, she revealed herself to be a vicious killer.