Heather Watson has become the first British woman to win a WTA singles title since 1988 with a triumph at the Japan Open.
The final was a topsy-turvy clash with both Watson and Chang carving out a total of 33 break points and breaking seven times each.
Watson broke four times in the first set but dropped her serve three times in the second, as her 21-year-old opponent came back into the contest.
Chang held three match points when serving in the 10th game of the third and final set and looked poised for victory when Watson fought back and won the title with her second match point in the tie-break.
Watson, who won the final in three hours and 11 minutes, had not previously progressed beyond the quarter-finals of a WTA event.