Azarenka broke three times in the first set and twice in the second as she claimed victory in one hour and 27 minutes.
Sharapova had her chances, particularly in the second set when she failed to convert any of her five break points, but her opponent punished her weak second serve.
An unforced error count of 39 - compared to Azarenka's 14 - helped tell the story.
The title was Azarenka's first since March.
She told the official WTA website: "To win the China Open is a dream for me, because I've never been able to do so well here - so to overcome that and win such a big title at the end of the year is just incredible. I'm really happy I came and I conquered here."
On the match, Azarenka added: "I was doing the right things, making sure I didn't let Maria play the game she likes, always being in control and dominating.
"Of course it wasn't possible for me to do that every single point, but for the most part I was trying to keep up with her rhythm, and when I had the chance just try to step it up and be in control myself. I tried to take that opportunity and move forward.
"As for her mistakes, I'm not really looking for them, but I'm looking to provoke them, looking to make them happen. She's not just going to stay there and miss - it's something maybe I've done to make her miss those balls."
Sharapova said: "Victoria played a really good match - she just did many things much better than I did.
"I felt like when I had the chance, in situations where I had opportunities to get back in the set or in the match, I was just making errors. They were little windows, but as small as they were, I just didn't take them. Against somebody who is number one in the world, you can't do that."