Ashleigh Barty took another giant step towards winning her first Australian Open title when the world No 1 defeated Amanda Anisimova in straight sets. Barty did see her run of 63 consecutive service holds come to an end when she was broken early in the second set but then went on to win six of the next seven games and sealed a 6-4, 6-3 victory over the American. Anisimova, who knocked out reigning champion Naomi Osaka in the previous round, made Barty work for her quarter-final spot but the home favourite used her backhand slice intelligently and consistently put the ball into the corners stifling the 20-year-old's power and rhythm. Barty praised Anisimova, who she defeated in a semi-final at Roland Garros in 2019 on the way to winning the French Open. “She's an incredible athlete, an incredible competitor, one of her best attributes is she turns up point after point after point,” Barty said in her on-court interview. “It's just nice to see her back playing her best tennis. She's going to be in a lot of deep stages of a lot of majors in her future, that's for sure.” Asked if beating Anisimova again was a good omen for winning her home Slam for the first time, Barty replied: "Well, we'll wait and see, hey?” Seeking to become the first local since Chris O’Neil in 1978 to win the Australian Open, Barty will play another American in Jessica Pegula for a spot in the semi-finals. Pegula stunned fifth seed Maria Sakkari to reach the last-eight at Melbourne Park for a second straight year. The 21st seed stormed through a first-set tiebreak and kept her foot to the gas in overpowering the Greek 7-6, 6-3 on Margaret Court Arena. “That was definitely my best match of the year,” said Pegula. “I thought I returned really well, I wanted to put pressure on her serve and I felt I did that. I was trying to be patient and play as smart as I could.” Pegula's compatriot Madison Keys had earlier joined her in the quarter-finals after the former US Open champion defeated eighth-seeded Spaniard Paulo Badosa 6-3, 6-1. Former US Open finalist Keys, who has slipped to 51st in the world rankings, booked her place in the last eight of a Grand Slam for the first time since the 2019 French Open with a comprehensive win over the Spaniard. “I think I served pretty well and I think I returned really well, so I think off of the first ball I had a little bit of the advantage on a lot of the points and was able to dictate,” Keys, 26, said. “I knew that I was going to have to take my chances and go for it because if I gave her an inch she was going to take it.” Keys will now take on French Open champion Barbora Krejcikova who kept alive her bid for a second Grand Slam title after cruising to a 6-2, 6-2 victory over an injury-hampered Victoria Azarenka. Azarenka, who won back-to-back titles at Melbourne Park in 2012 and 2013, received treatment to the left side of her neck and shoulder early in the second set and needed regular assistance from the trainer during changeovers. Fourth seed Krejcikova, who had never previously gone past the second round at the Australian Open, did not let her 32-year-old opponent's struggles affect her focus and sealed the victory on Rod Laver Arena when Azarenka found the net with a return. “It was really amazing because she's a champion here,” Krejcikova, who hit 23 winners and broke her opponent five times, said on court. “I have a lot of respect for her. I really admire her. “I'm extremely happy I won today, doing everything to get this win. I was really preparing for this, actually for a dream like this to play on such a court and play a champion. “I felt she was a favourite to the match. I was just enjoying the match and trying to play my best tennis. “Wow, I'm in the quarter-finals.”