The home invasion occurred as Francoise Jansen, 73, was watching the London Olympics on television Monday in her home in Weybridge, Surrey, The Daily Telegraph reported.
She told police two masked men burst in, tied her up and poured boiling water on her and subjected her to simulated drowning in an effort to get access to the safe.
The men never got what they wanted and eventually fled, leaving Jansen tied to a radiator. She said she was able to get loose by chewing on the bindings.
A police spokesman said Jansen suffered bruises and burns to her arms and shoulders. She is expected to make a complete physical recovery from her "horrific ordeal" but is also emotionally shaken.