The acute accent falls on the first syllable of jaya , in the sense of 'whereby one attains victory'.,
Thus ज꣡योऽश्वः, but otherwise जयो वर्त्तते ब्राह्मणानाम् ॥ The former जय is by प affix, 3.1.118 the second by अच् 3.2.31 ॥,
जयः करणम्
Adhyāya 6 · Pāda 1 · Rule 202