The 15th-seeded Frenchwoman remains on course to reach a second SW19 final after she emerged victorious from a rain-interrupted match against the 20-year-old American on Court No1.
“I thought I could have done better even today,” said Bartoli. “I could have closed out the match before.
“I really thought she played some amazing shots, especially when I was leading that game 5-3. She came up with some backhands down the line that were really amazing. I thought she fought extremely hard.
“She really played some great tennis today. She was running really well. On grass, it’s very tough.”
Bartoli, 28, will face Kirsten Flipkens for a place in the final after the Belgian overcame 2011 champion Petra Kvitova in three sets on Centre Court.
She added: “Tennis is kind of a crazy game, and now I am playing Kirsten Flipkens to be in the final of Wimbledon. So it’s also very unexpected, but that’s also the magic of it.”