Fourth seed Muguruza sealed a 7-5, 6-4 with an outrageous lob to banish the memories of losing last year's Wimbledon final against Williams and claim her first Grand Slam crown.

The 22-year-old has become her country’s first female champion at the French Open since Arantxa Sánchez Vicario in 1998.

"I'm so, so excited - to play in a Grand Slam against one of the best players, it's the perfect final," said the Venezuelan-born Spaniard.

"I'm so happy.

"I had to be very ready and concentrated on all the points and just to fight as much as I can.

"All the matches I've played against her helped me.

"It's our favourite tournament in Spain and I want to thank all my Spanish supporters."

Williams, 34, reached the final despite reportedly struggling with a thigh injury, but the top seed and world number one seemed to be moving freely from the outset. 

After Muguruza had seen off early break points, it was Williams who suffered the first blow by dropping serve with a double fault at 2-2. 

The defending champion appeared to regain the upper hand with three consecutive games putting her 5-4 ahead, however, Muguruza held serve to stay in the set before breaking for a second time to allow her to serve out the set.

The second set started with three breaks of serve, but it was Muguruza who remained in control, moving into a 3-1 lead.

Williams was unable to muster up a break point in the latter stages and fought bitterly to hold onto her crown, saving four match points on her own serve in a dramatic penultimate game.

Muguruza maintained her composure though and ultimately converted on her own serve with a magnificent lob before falling to the clay in celebration.

"Congratulations to Garbine, she played really well today," said Williams, who confirmed that she had been slightly troubled by an adductor problem.

"I could have served better, made a lot of errors on return, but I did try hard out there."

The men’s final between Serbia’s Novak Djokovic and Britain’s Andy Murray is scheduled to take place tomorrow.