Chain Sudoku

This is a variation of Sudoku and is very similar to Jigsaw Sudoku. There is a grid of 9 x 9 circles. The circles are further grouped into 9 groups of 9 circles each, the circles in a group are connected by horizontal, vertical, or diagonal lines. The object of the game is to fill each circle with a number from 1 to 9. The numbers in each row and column must not repeat, and so are the numbers in each of the connected groups. Thus Jigsaw Sudoku is essentially a subset of this game, where in Jigsaw Sudoku the connecting lines can only be horizontal or vertical, but in this game they can also be diagonal. Try to make use of all the clues to fill in the grid as soon as possible. The faster you finish, the higher your rank.