Shelby Rogers was reduced to tears after beating Irina-Camelia Begu to reach the quarter-finals of the French Open, while Garbine Muguruza moved into the last eight for the third year in a row on Sunday.
Rogers beat Karolina Pliskova and Petra Kvitova en route to the fourth round and the world number 108 continued her best run at a grand slam by dumping out 25th seed Begu 6-3 6-4 on Court Suzanne-Lenglen.
The unheralded American is only the ninth player from outside the top 100 to reach the quarter-finals at Roland Garros and will now face fourth seed Muguruza.
Muguruza, runner-up at Wimbledon last year, was a 6-3 6-4 winner against the 2009 French Open champion Svetlana Kuznetsova.
Second seed Agnieszka Radwanska was leading Tsvetana Pironkova 6-2 3-0 when play was suspended due to rain, while Simona Halep will return to Court 1 on Monday with a 5-3 advantage over Sam Stosur.
PRESSURE OFF FOR ROGERS
Rogers admitted she has surprised herself on the clay in Paris and the 23-year-old is eyeing further progress at the expense of Muguruza.
"It gets harder every round. I'm ready to step up to the challenge, I think. I have nothing to lose. I have no pressure. It's just been a great experience here, and I want to keep enjoying it and keep pushing myself," she said.
"I'm definitely outside of my comfort zone already, and I keep telling myself 'You belong here, you belong here. Play your game, do the things that got you to this moment. Don't change anything'."
MUGURUZA EAGER TO TAKE NEXT STEP
Muguruza produced a commanding display to get the better of Kuznetsova on Court Philippe-Chatrier, demonstrating how she has surged to number four in the world.
The 22-year-old is determined to take her place in the semi-finals for the first time at the clay-court major after crashing out at the quarter-final stage on her last two visits.
She said: "I think each tournament is different. I can't really compare things. Of course I'm very happy to have qualified this morning for quarter-finals. This is where I have stopped in the past, which means I'm extremely motivated to move on.
"But again, I don't really like to compare tournaments. Each tournament is different. Typically when I start a new tournament, I forget about everything I have done before or everything I have done the previous year."