O'Sullivan hit top form in the evening match as he thrashed Barry Hawkins 6-2, making three centuries as he did so.
That earned him a place in the final against Ding, who beat Joe Perry 6-4 in the other semi-final during the afternoon.
"I scored well but still gave him some chances, every frame he had a chance," said O'Sullivan.
"My long game was ok and my safety was alright. I felt like if I got a chance then I was going to do some damage. If he took some of his chances then maybe I would have tightened up, but I felt like I wanted to open up tonight and impose myself on the game.
"I am attacking a lot more now. It is not reckless to be attacking and I feel like I am seeing the balls a lot better."
On his final showdown with Ding he added: "Ding is the in-form player. If he wins this he will equal the record for ranking titles in a season. People talk about records but that record is worth having. You are a winner if you do that sort of stuff.
"For me it is a fantastic opportunity to see where I am at against probably the best player in the world on current form. I am just happy and enjoying my snooker. I am not getting too down on myself and trying to leave a legacy on the game.
"I probably would have won a lot more if I had found this sort of form earlier in my career, but it is better late than never."
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