Karolina Pliskova fought back from a set down to win a seesaw fourth-round encounter with Veronica Cepede Royg and progress to the French Open quarter-finals.
The second seed conceded after beating Carina Witthoft last time out that she had not been playing her best tennis and was surprised to have reached this stage, despite having not faced a player from inside the top 50.
And she looked to be in some trouble against world number 97 Cepede Royg, who had defeated Lucie Safarova and 16th seed Anastasia Pavlyuchenkova en route to the last 16, but edged out a 2-6 6-3 6-4 win to set up a quarter-final clash with Caroline Garcia.
Cepede Royg started extremely quickly and raced into a 4-0 lead in the first set, Pliskova handing her a second break with a double fault. Pliskova was unable to recover and a set in which she made 16 unforced errors went the way of the Paraguayan when the Czech sent a return long.
The second set was the antithesis of the first as Pliskova forged a 5-0 lead, only for Cepede Royg to hold to avoid a bagel and breed hope of turning things around by pulling back to 5-3 after staving off two set points.
But an unreturnable Pliskova serve out wide set up a decider, and the world number three's momentum continued unchecked as she broke for a 2-1 advantage in the third.
However, Cepede Royg, whose movement and skills at the net caused Pliskova problems throughout, immediately responded - breaking back with a delicate drop-shot.
The shock looked to be on the cards when Cepede Royg earned two break points at 3-2, but Pliskova avoided dropping serve again by showing impressive accuracy with her groundstrokes.
For all her good work, the decisive moment in the match came when Cepede Royg hit a simple forehand into the net with the court at her mercy, handing Pliskova a pair of break points.
Pliskova wasted no time in taking the first for a 5-4 lead and, despite some further Cepede Royg resistance, the 2016 US Open finalist held to reach a third successive grand slam quarter-final.
Pliskova  bt Cepede Royg 2-6 6-3 6-4
Pliskova - 22/35
Cepede Royg - 23/30
Pliskova - 4/5
Cepede Royg - 2/6
BREAK POINTS WON
Pliskova - 4/7
Cepede Royg - 4/10
FIRST SERVE PERCENTAGE
Pliskova - 54
Cepede Royg - 66
PERCENTAGE OF POINTS WON ON FIRST/SECOND SERVE
Pliskova - 72/40
Cepede Royg - 65/46
Pliskova - 85
Cepede Royg - 83