Roundup: Sinner powers into Australian Open final, Zverev advances after Djokovic retires

MELBOURNE, Jan. 24 (Xinhua) -- Defending champion Jannik Sinner downed Ben Shelton on Friday and powered into a second straight Australian Open final, where he will face Germany's Alexander Zverev after Novak Djokovic retired with a muscle tear.

In the later semifinal on Rod Laver Arena, top seed Sinner claimed his 20th straight victory after ruthlessly dispatching the 21st-seeded American 7-6 (2), 6-2, 6-2 in t