Jan. 28 (UPI) -- World women's No. 1 Ashleigh Barty won in straight sets and men's No. 3 Roger Federer needed another five-set thriller to advance to the semifinals at the Australian Open Tuesday.
Federer, 38, advanced to face defending champion and No. 2 seed Novak Djokovic in the penultimate round of the Melbourne tournament. He beat American Tennys Sandgren 6-3, 2-6, 2-6, 7-6 (8), 6-3 in Tuesday's quarterfinal clash. Just a few points away from losing the match, Federer didn't think he could turn it around until he fought back to win the fourth set in tiebreak.
"It was just a matter of coming to terms with what do I have and what don't I have in my game," Federer told reporters.
Sandgren fired 27 aces to Federer's five, but the Swiss star had just three double faults in the win. Sandgren hit 73 winners to Federer's 44.
"I'm tired," Sandgren said after the 3:31 match. "I'm emotionally tired, physically tired, just tired."
Federer needed 2:11 to beat Marton Fucsovics in a four-set fourth round match and needed nearly twice that time to win a five-set marathon against Australian John Millman in the third round.
Djokovic beat Canada's Milos Raonic in straight sets to reach the semifinals. Top seed Rafael Nadal has a quarterfinal match against Dominic Thiem and No. 15 Stan Wawrinka and Alexander Zverev face off in the remaining men's quarterfinal.
In the women's draw, Barty bounced Petra Kvitova 7-6 (6), 6-2 to advance to a semifinal matchup against American Sofia Kenin, who followed her fourth round win against American Coco Gauff by beating Ons Jabeur in the quarters.
"It's exciting," Barty said. "It's a challenge. I love it. I love testing myself against Petra. She has this way of bringing out the very best in me and she came at me with all guns blazing."
No. 4 Simona Halep faces Anett Kontaveit in the first women's quarterfinal Wednesday in Melbourne, and Anastasia Pavlyuchenkova battles Garbine Muguruza in the remaining women's quarterfinal.
"It's exciting and I'm happy. I'm doing this for myself," Kenin said. "I'm trying not to think about being the last American [remaining]. It's an honor and it's a privilege and I'm happy to be where I am."