Dominika Cibulkova was sensationally beaten in straight sets by lucky loser Ons Jabeur in the French Open second round on Wednesday, while Petra Kvitova also lost despite a creditable performance.
The absence of Serena Williams and Maria Sharapova, as well as the early elimination of top seed Angelique Kerber, has really opened up the women's draw at Roland Garros.
And, as sixth seed, 2009 semi-finalist Cibulkova will have considered herself in with a chance of going deep into this tournament.
However, the Slovakian was dumped out by surprise package Jabeur, who is yet to drop a set on her way to a third-round clash with Timea Bacsinszky.
Kvitova was unfortunate to lose out in a closely fought two-set encounter with Bethanie Mattek-Sands, while Ekaterina Makarova was unable to follow up her impressive win against Kerber.
Elsewhere, there was a thumping win for Caroline Wozniacki against Francoise Abanda, while defending champion Garbine Muguruza came from a set down to beat Anett Kontaveit.
CIBULKOVA STUNNED BY JABEUR
Jabeur pulled off her first victory over a top-10 player to maintain her unlikely run at Roland Garros.
The Tunisian world number 114 had already seen off one higher-ranked player in Ana Bogdan to reach the second round, but trumped that with her exploits on Wednesday.
After falling a break down to Cibulkova in the second set, Jabeur won five games on the bounce to become the first lucky loser into the third round since Gloria Pizzichini in 1996.
"I forgot already about being a lucky loser!" she said afterwards. "It was an unbelievable match for me. I think I played really good, and I made the necessary shots in this match."
KVITOVA DESERVES CREDIT
Kvitova's presence at Roland Garros is, in itself, a triumph, following her recovery from a hand injury inflicted by an intruder at her home in December.
But her involvement came to an end on Wednesday with a 7-6 (7-5) 7-6 (7-5) defeat to American qualifier Mattek-Sands.
The two-time Wimbledon champion has swiftly shifted her attention to the upcoming grass season and says it was always her primary focus.
"Coming to Roland Garros was one of the things we were [doing in] preparing for Wimbledon - we do have a lot of attention here," she said. "Wimbledon should be much more relaxed afterwards.
"I really am looking forward to being there. It's a really great tournament for me. I have the best memories which I can have."
MAKAROVA FALLS FLAT
Makarova caused the upset of the opening round when she toppled world number one Kerber in straight sets.
However, she was unable to carry her form into Wednesday as she was beaten by Ukraine's Lesia Tsurenko 6-2 6-2 - the same scoreline by which she had seen off Kerber.
Three dropped service games in the opening set put Makarova on the back foot and Tsurenko wrapped up the win with two breaks in the second.
She faces Jelena Ostapenko in round three.
WOZNIACKI DELIVERS BAGELS
Wozniacki needed just 52 minutes to sweep aside Canadian qualifier Abanda, winning 6-0 6-0.
"I felt I played really well today and hopefully I can just keep going," she said. "I felt like I have been very comfortable and confident all season, so hopefully I can just keep that going in the second half of the season."
Abanda commented: "I think that she played her second match. I played five matches. Physically, I couldn't sustain the challenge."
While it was disappointment for French Open debutant Abanda, Catherine Bellis shone on her maiden second-round appearance in Paris, beating 2016 semi-finalist Kiki Bertens 6-3 7-6 (7-5).
Wozniacki and Bellis meet in the next round.