Mihaela Buzarnescu dumped Elina Svitolina out of the Birmingham Classic, while top seed Caroline Garcia was beaten at the Mallorca Open on Friday.
Svitolina was the highest ranked player in the quarter-final draw in Birmingham, with Garbine Muguruza knocked out earlier in the week, but she too fell by the wayside.
Buzarnescu defeated Svitolina at the French Open and she came out on top in a second meeting in a matter of weeks, triumphing 6-3 6-2.
"I didn't go on the court thinking I played her three weeks ago," Buzarnescu said. "She's an amazing player, so young and so many achievements until now and so many to come.
"I just tried to go on the court, play my own game and focus on each point and take it as an ordinary match."
Buzarnescu moves into her first WTA Premier-level semi-final, where she will face defending champion Petra Kvitova, who breezed past Julia Goerges 6-1 6-4.
Barbora Strycova and Magdalena Rybarikova make up the last-four draw, Lesia Tsurenko's retirement handing the former victory while Dalila Jakupovic lost to the latter.
In Mallorca, Garcia went down 6-3 6-3 to Sofia Kenin, with Lucie Safarova, another seed, also knocked out by Tatjana Maria.
Teenager Kenin will now play the first WTA Tour semi-final of her career.
"I'm very happy. [Garcia] is a great player," she said. "It was a really tough match and I knew I had to fight until the end."
Alison Riske was defeated by Sam Stosur, and third seed Anastasija Sevastova came from behind to get past Ajla Tomljanovic 3-6 6-3 6-1.
|Runners and Ryders: Molinari impresses again as stars prepare for The Open|
|Macron to greet France team after Champs Elysees parade|
|Casillas and Suarez critical of VAR after World Cup final|
|TMO protocol clearly not working, says SANZAAR|
|Americans seek joy of six at Carnoustie, Rose out to end wretched run - The Open in Opta facts|
|Ronaldo arrives in Turin for Juventus medical|
|Stone: I had no idea what my score was!|
|The Open: A look back at Van de Velde´s Carnoustie calamity|
|Rakitic proud of ´brother´ Modric´s Golden Ball award|
|Serena can surpass Court, but Graf was the real target - Krajicek|
|Ronaldo moved to remain motivated - Kaka|
|Silva confident on Everton transfer targets|
|Golden Boot winner Kane aims to break August hoodoo|
|NFL training camp 2018: Contract holdouts and where they stand|
|Guardiola took me to another level - Alaba|
|Madrid selling Ronaldo a ´historic error´ - Calderon|
|MLS Review: LAFC, Atlanta held at home|
|Stones will watch re-runs of England´s World Cup matches|
|Ferdinand challenges Mourinho to unleash Pogba at United|
|Mbappe: I´m staying at PSG|
|Former NHL goalie Ray Emery found dead|
|Pirates secure five-game sweep of Brewers with walk-off win|
|WATCH: LeBron receives standing ovation at Lakers´ summer league game|
|Tony Romo wins celebrity-filled American Century Championship|
|McGregor praises Putin after attending World Cup final|
|Open-bound Kim claims maiden title with eight-shot triumph|
|Eagles running back Sproles plans to retire after next season|
|World Cup winner Rami retires from international football|
|Wimbledon champion Djokovic did not expect grand slam glory so soon|
|Ibrahimovic praises Pogba after World Cup final display|
|Wimbledon diary: Avengers too late for an Infinity War as Djokovic triumphs|
|Deschamp-agne – France´s 2018 vintage interrupt news conference to drench coach|
|I may have to dust my boots off! - Pele threatened by Mbappe exploits|
|WATCH: Mendy and Pogba dab with president Macron after World Cup win|
|Woods embracing ´different´ Carnoustie challenge ahead of Open return|
|Argentina dismiss Sampaoli after chaotic World Cup|
|France celebrates World Cup triumph|
|Djokovic made ´improvised Wimbledon trophies´ as a boy|
|Stone goes agonisingly close to 59 as Pepperell & Dantorp also make Open|
|Outcast Benzema delights in France win|
|Final a triumph in itself given Croatia´s off-field turmoil|
|Anderson laments Wimbledon final nerves|
|Deschamps joins elite club, Mbappe second to Pele - the best stats from the World Cup final|
|Belgium´s Courtois wins World Cup Golden Glove|
|Collarbone fracture confirmed for ´devastated´ Porte|
|World Cup final player ratings: Griezmann, Mbappe inspire France as Croatia fall short|
|World Cup winner Giroud ends tournament without shot on target|
|Modric wins World Cup Golden Ball|
|Mbappe wins World Cup Young Player award|
|Deschamps redeemed as France win World Cup final for the ages|
|France 4 Croatia 2: Twitter Report|
|Tomlin optimistic over Bell contract|
|Kane wins World Cup Golden Boot|
|Ajax keen on Blind deal - Van der Sar|
|France 4 Croatia 2: Pogba and Mbappe seal thrilling World Cup triumph|
|Anderson would have played another 21 hours to reach Wimbledon final|
|Djokovic delighted to crown ´comeback´ with Wimbledon glory|
|World Cup final interrupted by pitch invaders - Pussy Riot claim responsibility|
|Djokovic´s grass-court U-turn pays ultimate dividends with Wimbledon title|
|Mandzukic makes World Cup history with early own goal|
|Dominant Djokovic beats Anderson to regain Wimbledon title|
|Everybody said I´m done - Degenkolb revels in first Tour victory|
|´Big party´ for Marquez after Sachsenring success|
|Hazard enjoys Belgium´s welcome home|
|Ex-AC Milan president Berlusconi conflicted over Ronaldo to Juventus|
|Spain did not contact Martinez over head coach vacancy|
|Maybe the VAR was watching The Simpsons! - RSL coach Petke slams MLS officials|
|Cubs´ Darvish hopes to return by next weekend|
|France and Croatia name unchanged sides for World Cup final|
|Marquez maintains Sachsenring dominance|