ADELAIDE: Jelena Ostapenko, the former world number five, defeated Marta Kostyuk 7-5 6-3 to advance to the Adelaide International semi-finals, continuing her momentum ahead of the Australian Open. The 12th-ranked Latvian, who won the 2017 French Open to earn her first Grand Slam victory, is beginning to regain her best form ahead of the Australian Open, which takes place from January 14–28. She will face local favorite Kimberley Birrell in the opening round. The quarterfinalist from Brisbane, Ostapenko, prevailed over the fierce Ukrainian Kostyuk in the first set and then upped her game in the second, breaking to lead 3-1 after losing the first set.