Aryna Sabalenka won't win her third Australian Open in a row ... and, while she usually wins the break point, she reached her breaking point after the heartbreaking L -- taking it out on her trusty racquet.
The Belarusian tennis standout was playing American Madison Keys in the final ... and, ended up losing the third set 7-5, dropping two out of three after battling back down 1-0 to force a tiebreaker.
After a hard fought final point, Keys emerged victorious .