Muguruza, who beat Serena Williams to claim the 2016 title, came from a set down on Sunday to dispatch the unseeded American Taylor Townsend 5-7, 6-2, 6-2.
The 19th seed appeared edgy at the start of the encounter. Her ground strokes lacked their usual length and punch. Townsend exploited the timidity and broke to lead 4-2. But she squandered her advantage immediately and the Spaniard levelled at 4-4.
However she eventually succumbed when serving to take the set into the tiebreak.
But from 1-1 in the second set, Muguruza took control. She broke to lead 2-1 and never looked back.
“It’s a wonderful court,” said Muguruza after her first round success. “You feel very close to the spectators.”
Following the victory, the venue was officially anointed. Bernard Giudicelli, the head of the French Tennis Federation, was joined on the court by Bertrand Mathieu, Simonne Mathieu’s grandson, as well as former French Open champions Mary Pierce and Francoise Durr.
Marc Mimram, the architect who designed the court, said: “It’s very difficult for an architecht to know what is going to happen. But the ambiance is very good.
“I was nervous before the first ball was hit but everyone seems to like the court. I am very happy.”