Muguruza the bigger striker of the ball, had only 14. The Russian won only five of 26 second-serve points in the face of Muguruza's elegant 6-2, 6-1 stampede.
Another grand slam chance for Simona Halep.
"I was 2-4 down in the second set but I knew I had to fight for every ball, push her back and play the way I did in the first set". "So I think that's why I won today", Halep said. "My head won it", Halep said. Halep is 3-2 in career grand slam semifinal matches.
It was the first set that the Wimbledon champion had dropped at Roland Garros this year.
Nadal lost the opener 6-4 against 11th-seeded Diego Schwartzman but began to play better after a rain delay of just under an hour.
The 24-year-old improved in the early stages of the second set, holding serve for the first time and backing it up with a break on her way to a 3-1 lead.
After being washed out by rain on Wednesday, Rafael Nadal and Juan Martin del Potro set up a semifinal showdown on the men's side.
However, her sights now turn to the final where she is desperate to erase the memories of last year's horror show where she surrendered a set and a 3-0 lead to lose to Jelena Ostapenko. She's clear on who she is as a player.
It will be Halep's second consecutive Grand Slam final after she lost the title match at the Australian Open in January.
"To have had the victories that I have had, to have the results that I have, obviously moving a step in the right direction", said Sharapova who had made the last 8 in Madrid and semis in Rome in the run-up to Paris.
Sharapova certainly didn't do that.
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The first lady later tweeted several photos of the event, including two of her seated alongside the president. Grisham told ABC News last Wednesday that the first lady was "doing really well".
A nervous start from the Spaniard was immediately pounced upon by Halep for a break in the opening game. "Coming into this part of the year, I was losing a few first-round matches, matches that I wanted to be winning, of course".
For comparison, Muguruza needed 70 minutes to beat Maria Sharapova in the quarterfinals.
Sharapova didn't play a point in the fourth round, because Serena Williams pulled out of their much-anticipated showdown with an injured chest muscle.
Muguruza's opponent Lesia Tsurenko lasted just two games before retiring hurt. It wasn't just the body "absorbing all of the wear and tear", Murray said, but absorbing it "all of a sudden".
At 5-foot-6, Halep is giving away a full six inches to Muguruza. The most recent match was in the 2017 Cincinnati Masters, a match Muguruza won in 13 games.
This is the first all-American French Open semi-final since 2002, when Serena Williams defeated Jennifer Capriati en route to the title. But she failed to convert any of those, and Halep held there, before breaking at love to end it.
Halep was the runner-up in 2014 and 2017.
Muguruza, a two-time major champion, entered the semifinals having not lost a set in the tournament.
Like Sharapova, Halep trailed 4-0 at the outset. In the first set, Halep had 30 unforced errors.
But Halep figured things out.
"Life came at me fast after the U.S. Open", said Stephens, whose late father, John, was the 1988 NFL Offensive Rookie of the Year with the New England Patriots. "I have two more days until I will play the final". Some of those matches were very defining for me.