158 FIRST PRINCIPLES OF BUSINESS LAW warranty rather than a breach of a condition (unless the parties have expressly agreed otherwise). The substantial performance must be accepted and paid for proportionately. Isaacs was therefore required to pay the agreed price, less the amount needed to rectify the defects. Connor v Stainton (1924) 27 WALR 72 Contract; performance of a contract; substantial performance; breach of contract. Facts: Connor entered