Williams won on temperament. Higgins hedged that blue. He did everything right up to that, approaching the brown on the right side to allow the blue to cover the brown if he missed. But when he got on the blue, he hedged. That was fatal. One thing about Williams is he'll never die wondering. Higgins will have sleepless nights over that.
That said, Wiliams had the big mo. From 1-5 down, he led 12-8. That's 11-3 over the bulk of the match. Dominant. Only Higgins's bottle kept him afloat. To retrieve 8-12 was some going. But he had his chances and was steamrolled through the middle of the match. If you can't capitalise on a good start AND a good finish, you can't have too many complaints. Both are marvels, however.
As for the semi, I don't give Williams a prayer from here. Assuming it is Trump, I'd expect a one-sided Trump win - at least in terms of the general flow of the match - with Williams making him sweat towards the end by coming back from the dead when the result has largely been decided.
O'Sullivan-Trump for me with Ronnie winning again. Zhao remains the wild card, however...