Kim Kardashian says Kanye West's marriage proposal was the "surprise of a lifetime".

The 'Stronger' hitmaker asked the brunette beauty to be his wife in front of all her loved ones at AT&T Park in San Francisco on her 33rd birthday last October and Kardashian - who has eight-month-old daughter North with the rapper - later admitted she had no idea what was going to happen.

Speaking on 'Keeping Up with the Kardashians', which aired the proposal Sunday night, she said: "I'm, like, shaking. It is so crazy to me that this is all happening. Kanye really outdid himself. It feels like I'm in a dream. It's just the most amazing experience. I am the biggest investigator, so the fact that I didn't see one sign of this happening is the surprise of a lifetime."

Kardashian wasn't the only one impressed by West's proposal, which saw an orchestra play Lana Del Ray's 'Young & Beautiful' as fireworks went off and the words 'Pleease marry meee!' appeared on a screen as the rapper got down on one knee.

Her sister Khloe Kardashian said: "I really am in a movie right now. This is so spectacular. It's so stunning and breathtaking...it's truly a magical moment."

While West initially wanted a smaller diamond for his fiancee's ring, she was overjoyed with the 15-carat stone.

She said: "It really is the most beautiful thing I've ever seen. I just can't believe I'm engaged."

Only Kardashian's mother Kris Jenner knew exactly what West was planning and she was full of praise for her future son-in-law.

She said: "I know firsthand the real Kanye. He is a sweetheart with a huge heart for everyone that he loves. He's so many things that I don't think a lot of people get the chance to see."