boilover

noun

1. (countable, uncountable)A hazardous situation where an attempt is made to extinguish semi-enclosed oil- or petrochemical-fuelled fire with water, generating steam which propels the burning fuel outwards.
2. (Australia, New-Zealand, countable, slang)A sporting event with an unexpected outcome, especially a horse race where the favourite fails to win.

   “[…] there was not much good horsemanship. The Derby itself was an ordinary race, something of a boilover for Dark Star […]”