One-off and World-beater

One-off noun - A happening that occurs only once and is not repeated.

World-beater and one-off are semantically related. In some cases you can replace phrase "World-beater" with "One-off", this phrases are similar.

World-beater noun - A competitor who holds a preeminent position.

One-off and world-beater are semantically related. You can use "One-off" instead a noun phrase "World-beater".