a down the middle forehand return long to drop the set 6-1 in only 23 minutes.
The Romanian suffered another poor start to set two as she quickly trailed 0-3 following more forceful play from Muguruza.
Halep then struck two groundstroke errors to lose a seven deuce, twelve minutes long game, the longest of the match to fall behind 0-4.
Serving down 0-4 15 all, Halep netted an on the run crosscourt forehand passing shot to trail 15-30 before striking a crosscourt forehand wide to reach 15-40.
Muguruza would break serve to lead 5-0 after Halep sent a crosscourt forehand volley long on breakpoint.
With the Spaniard serving for the match, Halep struck two forehand errors to trail 0-30.
Halep then hit an inside out crosscourt backhand return wide to face triple match point.
A final inside out forehand down the line from Halep landed wide to end the match.