The first of God's works was..........Behemoth.
Job 40:19 He is the reshit (firstling) of the ways of El; He, his Maker, can approach it with His cherev (sword).
OK, where to start. First of all, yes the word in context does imply 'first'. But even if you apply the extended definition of "best, or greatest". the text is troublesome without appreciation of the meaning of Behemoth.
The creation stories throughout ancient word involved the vanquishing of chaos, often represented as the restless sea or untamable beast/monster. The OT has this imagery many times and informs many narratives involving dividing water. In this section of Job the author is describing one of the Hebrew forms of this legend. Instead of a single beast there are two, one in the sea, Leviathan and one on the earth, Behemoth. Note that the ferocity of the Behemoth is such that only God can approach it with his sword. Thus demonstrating his control over his creation.