The phrase "first division" refers to the highest level or top tier of a particular group or organization. It indicates that those in the first division are considered the best or most skilled in their field. Full definition
We are the only club in First Division / premier league to have never been relegated (justarsenal.com)
A league championship in 1973/74 was the pinnacle and ironically, Leeds were the last side to win the old first division title before the Premiership era heralded United's dominance. (manutdnetwork.com)
It was one of Pollock's signal accomplishments to give such magnitude and impressiveness to the act of painting as to make us think of the mysteries of natural creation, of that «first division of chaos» at the origin of our world. (visual-arts-cork.com)