Swimming-Cate Campbell ties own 2016 mark at Japan Open

TOKYO, May 22 (Reuters) - Australia's Cate Campbell underlined her status as favourite for 100 metres freestyle gold at the Rio Olympics when she matched her world leading time of 52.38 seconds at the Japan Open. The 24-year-old London relay gold medallist has been in strong form this year and eclipsed her injury-hampered younger sister Bronte, the reigning world champion in the blue riband sprint. Her time at Tokyo's Tatsumi International Swimming Center late on Saturday matched the 52.38 she swam at the Australian Olympic trials in Adelaide in April, which was the fifth fastest of all time. Bronte was third in Tokyo but is still the second fastest woman over the distance this year, her 52.58 at the Australian trials keeping Sarah Sjostrom (52.78) in third place on the 2016 time sheets. Sjostrom is looming as the greatest threat to the Campbell family's hopes of gold in Rio and the Swede coasted to 100 frestyle victory in the European championships in 52.82 on Wednesday. (Reporting by Nick Mulvenney in Sydney, editing by Peter Rutherford)