Kim Kardashian shows off 15-carat engagement ring

Kim Kardashian had two big reasons to celebrate Monday -- it was her 33rd birthday, and Kanye West popped the question.

The "Keeping Up with the Kardashians" star shared a new photo of the massive sparkler he proposed with.

Kardashian posted that picture on Instagram, with a one-word caption: "YES!!!"

West, 36, proposed to Kardashian with the 15-carat, square-cut ring by jeweler Lorraine Schwartz (who also designed her previous engagement ring from ex-husband Kris Humphries, which recentlysold for $749,000 at auction), E! News reports.

The proposal took place at San Francisco's AT&T Park, where the rapper arranged for a 50-piece orchestra to play songs by Lana Del Rey, Keri Hilson and Ne-Yo as "PLEEEASE MARRY MEEE!!!" was displayed on the stadium's giant screen.