The first set had a level start but Muguruza quickly seized the initiative. In the second set the game was nerve-wracking after Ostapenko seized the initiative and went on to win the second set after scoring successive precise shots.
The third set however saw a demotivated Muguruza succumb to Ostapenko who showed a convincing game that earned her the French Open title this summer.
This is the eight successive victory for Ostapenko, and her first against Muguruza whom she had faced two times before. Ostapenko has earned 350 WTA points for advancing into the Wuhan semis.
She will face Australia's Ashleigh Barty (WTA 37) on September 29.