The fourth seed moved into the quarter-finals for the third year in a row with a solid display as she looks to become the first Spanish woman to lift the Suzanne Lenglen Cup since Arantxa Sanchez Vicario in 1998.
Hard hitter Muguruza, who has yet to make it to the last four in Paris, left little breathing space for the Russian 13th seed, the 2009 Roland Garros champion, in a style different to that of Sanchez Vicario, a pure claycourt specialist.
"I know maybe now I'm more a favourite, but I could have lost two days ago," Muguruza told reporters.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
The Wimbledon runner-up believes she is now better equipped to go a step further.
"I think the one thing that I have really improved is not just one type of shot. It's me, generally speaking. It's me -- it's the way I prepare matches," she said.
"I think I have more experience. When I win I analyse why. When I lose I analyse why. And therefore, I have become a better player, generally speaking.
"It's not that I have improved my forehand or anything specific."
Muguruza peppered the court with winners -- which made up for numerous unforced errors -- and broke decisively on her seventh opportunity to lead 5-3 in the opening set.
She closed it out with a booming forehand winner and broke again in the third game of the second set with a service return winner.
Kuznetsova saw a lifeline when she broke back to 4-4 as Muguruza started to get inconsistent, only for the Spaniard to break again in the following game with a fine passing shot.
Muguruza, however, showed signs of nerves and wasted two match points before serving a double fault. She regained her composure, though, and wrapped it up on her fifth match point when Kuznetsova's backhand sailed long.
The Spaniard will next face either American Shelby Rogers or Romanian 25th seed Irina Camelia Begu.
(Editing by Clare Fallon)
