First Place
First Rank
noun
You have the ordinal number prefix and 一位 (first place). By adding the prefix 第, you can make it a little more formal, but it still means first place.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
第一位にえらばれる
to be elected to first place
第一位にする
to elect to first place
第一位になる
to become first place
この作品は作文コンクールで第一位でした。
This work got first place in the writing contest.
もしその試合に勝ったら、彼は世界ランキング第一位になります。
If he wins that game, he'll become first in the world rankings.
今までずっと社内で売り上げ第一位だったのに、新人にその座を取られそうです。
Even though we have been first place in sales at the company until now, it is likely that a newcomer will take our spot.