Verb
tip the balance (third-person singular simple present tips the balance, present participle tipping the balance, simple past and past participle tipped the balance)
Synonym of tip the scales
It's unbelievable what one squadron of twelve aircraft did to tip the balance. Adolf Galland
For every bad thing in life, there are more good things to tip the balance. Richelle Mead
Those nations have a very great responsibility at this juncture of the world's affairs, for by throwing their joint weight into the scales of history on the right side, they may tip the balance decisively in favour of peace. Arthur Henderson