hole in one

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The driving of a golf ball from the tee into the hole in a single stroke.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun golf A hole that is completed by sinking the ball in a single shot or attempt, with one hit.
• noun by extension, idiomatic Any rare, wonderful, or remarkable accomplishment.