Sydney - Former champion Agnieszka Radwanska ended Johanna
Konta's Sydney International defence with a 6-3, 7-5 win on Tuesday to advance
to the second round.
The fourth-seeded Konta was playing her first match since
retiring from her Brisbane International quarterfinal last week with a hip
Third-seeded and French Open champion Jelena Ostapenko, No
5-seeded Kristina Mladenovic, sixth-seeded US Open winner Sloane Stephens and
No 8-seeded Anastasija Sevastova also lost their first-round matches.
Angelique Kerber was scheduled to play second-seeded Venus
Williams later on Tuesday.
Former US Open champion Samantha Stosur won her first-round
match, beating Carina Witthoeft 4-6, 7-5, 6-3.
In men's first-round play, Leonardo Mayer had a 7-5, 6-3
upset win over eighth-seeded Mischa Zverev.