102nd-ranked teenager Aryna Sabalenka at the Tianjin Open on Sunday before winning her first title since her 15-month doping ban.
The former world number one, who returned to action in April, came from behind in both sets and needed four championship points in the tie-breaker before beating the 19-year-old 7-5, 7-6 (10/8).
Sharapova clasped her hands to her chest in delight as she absorbed the feeling of winning her 36th tour title and first in more than two years since the 2015 Italian Open.
Sharapova, 30, was contesting the seventh tournament of what has been an injury-plagued and controversial comeback since testing positive for the banned substance meldonium in early 2016.
She exchanged 11 breaks of serve with the Belarusian, who has yet to win a WTA trophy, before finally clinching it in the tie-breaker when the teenager put a forehand return long.