Maria, a mother of two, returned from maternity leave a year ago and won a set 5-7, 7-5, 7-5 against the 2017 French Open champion.
This sent the 34-year-old to the first Grand Slam semifinal of his career.
With that feat, the German matched the feat previously managed by only six women, as she became the seventh woman to reach the last eight of the Major after turning 34 in the open era.
Maria, ranked 103rd in the world for saving two match points in the second set, has included the great Billy Jean King, Virginia Wade, Chris Evert, nine-time Wimbledon champion Martina Navratilova, Serena Williams and Venus Williams in the elite list.
Ostapenko was in a bad mood as the match slipped out of his hands and he was greeted warmly as he walked out of the court.
This could not be a special day for Maria, who said in her on-court interview: “Oh my God, I’m so proud to be a mother.
“It’s the best thing in the world, I love being a mother, I love my two kids. To be able to do this together, we practiced with my daughter this morning.
“Everyone is so nice, supporting us and trusting me and our family, it makes it really special.”
Maria’s next match will be against compatriot Jules Niemeyer, who defeated Britain’s Heather Watson in a straight set.
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