quit while one is ahead

quit while (one) is ahead

To cease, end, or give up (doing) something in which one has found some amount of success, especially so as not to risk spoiling or reversing that success. Look, that's good enough for what we need, so let's just quit while we're ahead. If we monkey around with the settings too much, we could screw the whole thing up. As soon as I made a bit of a profit playing poker, I decided to quit while I was ahead—no sense ending the night worse off than I began. I appreciate your compliment, but you should quit while you're ahead, because you're starting to veer off into creepy territory.
See also: ahead, quit, while
Farlex Dictionary of Idioms.

quit while one is ahead

to stop doing something while one is still successful. When will I learn to quit while I'm ahead? Get into the market. Make some money and get out. Quit while you're ahead.
See also: ahead, one, quit, while
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

quit while one is ahead

in. to stop doing something while one is successful. Get into the market. Make some money and get out. Quit while you’re ahead.
See also: ahead, one, quit, while
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions
See also:
  • quit while (one) is ahead
  • quit while one's ahead
  • rise like a rocket
  • rise like a rocket (and fall like a stick)
  • ride on the back of (something)
  • key to success
  • dress for success
  • hang on (one's) coattails
  • coattail
  • nothing succeeds like success