Already wide open in the absence of Serena Williams, the women's singles draw at Wimbledon became even more difficult to predict as Magdalena Rybarikova came from behind to upset Karolina Pliskova on Thursday.
A host of players outside the WTA rankings' higher reaches have an opportunity to claim grand slam glory at the All England Club this month, as evidenced by Jelena Ostapenko's surprise French Open triumph.
Without a clear favourite to back, Pliskova was touted by many as a likely contender, but the world number three did not have a track record at SW19 to inspire confidence, having bowed out in the second round during each of the last four tournaments.
And that fate befell her again on Centre Court, as Rybarikova, the Slovak world number 87, won 3-6 7-5 6-2 after an arm wrestle that lasted two hours and 17 minutes, setting up a meeting with Ukraine's Lesia Tsurenko in round three.
Having extended her record on grass this year to 15-1, perhaps it is Rybarikova who can go deep into the tournament, with two third-round appearances her best showings to date.
A closely fought first set was ultimately decided through a combination of Pliskova's brilliance and a stroke of luck.
The third seed fired off a clean winner to decide a rally and then benefited from a net cord to earn break point in the eighth game. The Czech pounced by running around her opponent's second serve to smack back a powerful forehand and force an error, before holding to love to take the set.
A pair of Rybarikova errors put Pliskova on course for a simple win, but she could not consolidate the advantage, as a Rybarikova forehand down the line earned her a break back point, which the Czech surrendered by spraying a tentative backhand wide.
Rybarikova's movement and persistence contributed to Pliskova faltering as the set neared its conclusion, a sequence of two missed smashes and two long forehand rally balls costing the favourite both a break and the set to send the match to a decider.
Mounting tension was prevalent as both players began to err more frequently as they traded breaks, but Rybarikova was the one to regain her composure, mustering a stunning forehand winner on the run from a wide position before holding to close in on the upset victory, which she secured with a backhand winner into empty court on Pliskova's serve.
Serving up a *massive* upset....-- Wimbledon (@Wimbledon) July 6, 2017
Magdalena Rybarikova downs No.3 seed Karolina Pliskova 3-6, 7-5, 6-2 in the shock of the tournament so far pic.twitter.com/KLMrognL27
Rybarikova bt Pliskova  3-6 7-5 6-2
Pliskova - 28/28
Rybarikova - 33/26
Pliskova - 6/2
Rybarikova - 6/1
BREAK POINTS WON
Pliskova - 3/11
Rybarikova - 5/6
FIRST SERVE PERCENTAGE
Pliskova - 62
Rybarikova - 51
PERCENTAGE OF POINTS WON ON FIRST/SECOND SERVE
Pliskova - 63/56
Rybarikova - 66/56
Pliskova - 94
Rybarikova - 99