Melbourne, Jan 23 : Jannik Sinner on Tuesday secured a spot in the semifinals of the Australian Open by defeating Andrey Rublev in straight sets, 6-4, 7-6(5), 6-3, here at the Rod Laver Arena. The Italian rising star has now advanced to the final four without dropping a set in the tournament. Sinner's victory was particularly highlighted by his resilience in the second-set tiebreak. Trailing 1-5, he mounted an impressive comeback, winning six consecutive points to claim the tiebreak 7-5. This pivotal moment proved crucial in preventing Rublev from leveling the contest and showcased Sinner's mental fortitude on the big stage. The 20-year-old Italian will now face the formidable challenge of Novak Djokovic in the semifinals. Djokovic, the top seed and 10-time champion, endured a tough battle earlier in the day against Taylor Fritz, eventually securing a four-set victory to reach his 11th Australian Open semifinal. For Andrey Rublev, it marks another missed opportunity in his quest to reach the last four at a Grand Slam event. The 26-year-old Russian has now faced defeat in all 10 of his Grand Slam quarterfinal appearances. /IANS