Tatjana Maria has rallied from a set down to defeat fellow German outsider Jule Niemeier 4-6 6-2 7-5, continuing her march towards a most unlikely spot in the final.
The world number 103 is only the sixth woman in the open era to reach the Wimbledon semi-finals after turning 34, joining legends Billie Jean King, Chris Evert, Martina Navratilova and Serena and Venus Williams.
Croat Mirjana Lucic at the 2017 Australian Open is the only other European player to achieve that feat at any of the majors.
Bidding to become the first tennis mum since Australian Evonne Goolagong Cawley in 1980 to win Wimbledon, the mother of two also recovered from a set down to beat 2017 French Open champion Jelena Ostapenko in the fourth round.
Niemeier, 22, was a qualifier at the French Open, losing in the first round in her only other appearance at a grand slam tournament.
Maria is making her 10th appearance at the All England Club, and her best previous performance was reaching the third round in 2015.
She has not made it that far at the other three majors.
Outside the top 250 as recently as March, Maria had lost in the first round at the 2021 US Open and 2022 Australian Open and French Open since returning from maternity leave.
But that has changed on the grass courts of London's SW19.
She beat three seeded players in a row in her run to the last eight — Sorana Cirstea in her second match, fifth seed Maria Sakkari in the third round and Ostapenko in the last 16.
Maria will now go on to face good friend Ons Jabeur, the highest-ranked player in the draw, after she recovered from a set down to beat Marie Bouzkova and reach the Wimbledon semi-finals for the first time.
The Tunisian third seed triumphed 3-6 6-1 6-1 on Tuesday to move to within two victories from becoming the first African woman to reign at the All England Club.
AAP/ABC Sport
