Breaks at the start of both sets sent Muguruza on her way to a 6-2, 6-3 win and a meeting against CoCo Vandeweghe.
Muguruza fell at the last 16 in both 2014 and 2015, but never looked in danger of suffering another disappointment, making light of her ongoing leg injury to strike 18 winners in little over an hour on court.
The ups and downs of previous rounds were conspicuous by their absence as the Spaniard hit the front early and rode this momentum all the way to the finishing line.
"I am very happy. I went through the match very concentrated, looking to play positively," Muguruza said. "Was an important match for me. A couple of times in the last three years, I've lost in this round. Was the first time I go through. I'm in the quarterfinals. So I'm very excited about that, and I'm still excited!"
Muguruza is arguably playing her best tennis since winning Roland Garros last spring. But with the World No.1's conqueror up next, she insists a repeat result is still some way off: "I think it's a very different surface. It's already a long time since that tournament. I feel that's very far away. Honestly, I would not compare the level.
"I've played CoCo a couple of times. It's 1-1 head-to-head. She's a tricky player. She has a lot of power, full shots, serve, everything. She can play very well."