Gavrilova injury sees compatriot Stosur advance in Prague
The all-Australian first-round clash at the Prague Open was cut short when Daria Gavrilova retired at one set apiece against Samantha Stosur on Monday.
Gavrilova lost the first set 6-3 but hit back to force a decider by winning the second 6-4 on the opening day of the tournament.
The fourth seed was unable to continue, though, after suffering a foot injury when she stretched to reach a backhand, so Stosur's four-match losing streak was brought to an end.
Natalia Vikhlyantseva will face home favourite Petra Kvitova in round two after seeing off Carina Witthoeft 6-4 6-4.
Eighth seed Katerina Siniakova made it through in her homeland with a 6-2 7-6 (7-4) victory over Andrea Petkovic, while Anna Karolina Schmiedlova, Tamara Korpatsch and Ekaterina Alexandrova also advanced, along with Wang Qiang and Antonia Lottner.
Kirsten Flipkens saw the back of third seed Petra Martic in the first round of the Grand Prix de Sar la Princesse Lalla Meryem.
Martic saved three match points, but was unable to prevent a 3-6 6-2 6-4 defeat in Rabat.
Zarina Diyas was another seed who fell at the first hurdle, losing 6-4 6-4 to Sara Errani. Sara Sorribes Tormo, Johanna Larsson and Jana Fett avoided early exits in Morocco.