Angelique Kerber and Garbine Muguruza both withdrew early from their second-round matches at the Stuttgart Open on Thursday, disappointing the fans in attendance at the evening session.
World number 12 Kerber, a champion at this WTA Premier event in 2015 and 2016, was struggling with a thigh injury against the unseeded Anett Kontaveit and decided enough was enough at 6-0 2-0 down.
Kerber had taken a medical time-out at 5-0 in the first, but treatment failed to sufficiently ease the problem.
The former US Open champion was forced to bow out to present Kontaveit with a safe passage to the quarter-finals, where she will take on Anastasia Pavlyuchenkova, who was next on court against second seed Muguruza.
The pair traded breaks in games eight and nine of the opener before, with Muguruza serving at 5-6 down, Pavlyuchenkova ripped a forehand up the line for break point and then watched the Spaniard send one long.
Although Muguruza showed no obvious signs of discomfort, the world number three got up from her chair before the second set got under way and shook hands with the Russian while the Stuttgart crowd voiced their disapproval at a second straight retirement.
What a pity! After Angelique Kerber and Marketa Vondrousova, @GarbiMuguruza is also forced to retire in her R2 match against @NastiaPav!— Porsche Tennis (@PorscheTennis) April 26, 2018
Therefore, Pavlyuchenkova is the last player, who secures a quarterfinal ticket.
Congrats, Anastasia! Get well soon, Garbine! #PTGP2018 pic.twitter.com/0XmPjiMDrN
Defending champion Laura Siegemund - who lost to Kerber in the final two years ago - saw her hopes of successive crowns ended by a 6-4 4-6 6-3 defeat to Coco Vandeweghe, who will face top seed Simona Halep.
Kerber and Muguruza were not the only retirees on the day as Elina Svitolina was 2-6 6-1 3-2 to the good over Marketa Vondrousova before the Czech pulled out.
Svitolina's quarter-final opponent comes in the form of Caroline Garcia, while Karolina Pliskova will face Jelena Ostapenko after their respective wins on Thursday.
|Mourinho hails ´amazing´ Chiellini and Bonucci after Juventus outclass United|
|Simeone glad to have Costa back for Dortmund clash|
|Lopetegui to remain in charge for El Clasico - Butragueno|
|Isner saves two match points to beat Norrie, Federer grinds out victory|
|Icardi happy at Inter ahead of Barca return|
|Marcelino satisfied with point after Valencia hold on at Young Boys|
|Hoffenheim 3 Lyon 3: Joelinton rescues a point after Kramaric´s double|
|Ajax 1 Benfica 0: Last-gasp Mazraoui seals dramatic win|
|Roma 3 CSKA Moscow 0: Dzeko turns on the style|
|Kovac lauds dominant Bayern|
|Shakhtar Donetsk 0 Manchester City 3: Silva sparkle to dominant display|
|Manchester United 0 Juventus 1: Dybala downs Mourinho´s men on Ronaldo´s return|
|Real Madrid 2 Viktoria Plzen 1: Benzema and Marcelo´s goals give holders first win in six|
|Lakers´ Rondo denies spitting on Rockets´ Paul|
|Robben and Rafinha want more from Bayern|
|Federer survives Krajinovic scare to maintain Basel run|
|Green accuses NBA of double standards, calls Lakers-Rockets suspensions ´garbage´|
|New York Giants send Apple to Saints|
|Morgan aims to solve Colombo mystery after record ODI defeat|
|AEK Athens 0 Bayern Munich 2: Lewandowski helps to further ease Kovac woes|
|Young Boys 1 Valencia 1: Hoarau penalty denies Marcelino´s men|
|Mourinho walks to Old Trafford as United arrive late again for Champions League|
|Bale and Benzema back for Madrid as Lopetegui rings changes|
|Carr denies ´fractured relationship´ with Raiders team-mates|
|De Bruyne to start for Manchester City against Shakhtar Donetsk|
|France lose Le Roux and Fofana for November Tests|
|Martino to leave Atlanta United amid Mexico links|
|Pochettino cautious over Eriksen return|
|Ancelotti an inspiration for PSG boss Tuchel|
|Persepolis 1 Al Sadd 1 (2-1 agg): Iranians into first AFC Champions League final|
|Wales boss Gatland returns to New Zealand after father´s death|
|Sri Lanka hand England their heaviest ODI defeat|
|Nuggets guard Will Barton undergoes surgery|
|Surprise package Svitolina closes in on semi-final berth|
|Alexander-Arnold targets glory at home and abroad|
|Pogba relishing emotional Juventus reunion|
|Alba hopes Lopetegui keeps Real Madrid job|
|Valverde not expecting Messi magical recovery|
|Wozniacki calms fears over knee injury|
|Maybe it´s my interviews - Klopp on Liverpool´s room for improvement|
|Language no barrier to Dortmund dangermen Reus and Alcacer|
|EPCR confirms no replay of Bath-Toulouse Champions Cup fixture|
|F1 Raceweek: Five the magic number as Hamilton eyes Mexico repeat|
|RFU to introduce in-season breaks for players|
|Nainggolan misses Barcelona trip|
|Wozniacki battles through knee complaint to down Kvitova|
|Alcacer: Two seasons at Barcelona not lost|
|Henderson, Keita to miss Liverpool´s Red Star clash|
|Khabib holds talks over Mayweather Moscow fight|
|Wolf in for Titz as Hamburg try to stop slump|
|Davies released from Wales squad as Evans comes in|
|Mbappe on track to match Messi and Ronaldo, says Giuly|
|Coleman, Kipchoge and Lyles among IAAF Male World Athlete of the Year shortlist|
|Serena Williams will win slams again sooner or later, says Seles|
|You always want the best – Ter Stegen open to Neymar return|
|Xavi: My teams will never use Mourinho´s style|
|I knew what I got myself into - LeBron appreciates Lakers are a work in progress|
|Mourinho: Ronaldo loves United but he will want to score|
|Cooper completes Rebels move and takes parting shot at Reds coach Thorn|
|Bellerin amazed by ´born champion´ Ozil|
|Penguins, kangaroos and ´Stone Cold´ Steve Austin: Halloween comes early for Trail Blazers|
|Ronaldo gunning for United, Aguero targets double record - Champions League in Opta numbers|
|Ill Vardy couldn´t stomach penalty decision – Puel|
|LeBron´s Lakers lose again, Magic stun Celtics|
|Bartomeu: No Barca return for Neymar, Valverde contracted until 2020|
|Simmons and ´stimulating´ 76ers in NBA Finals mix, says Longley|
|Falcons heap further misery on Giants|
|Vidic hails Ronaldo as ultimate professional ahead of Old Trafford return|
|Warriors´ Cousins nearing NBA return|
|Pogba can´t do the basics – Souness criticises Man United star|