Melbourne, Jan 23 : Poland's Magda Linette stunned World No.4 Frenchwoman Caroline Garcia in straight sets to reach her first Grand Slam quarterfinal here on Monday. Playing in her 30th Grand Slam main draw, Linette registered a 7-6(3), 6-4 upset win over WTA Finals champion Garcia in 1 hour and 57 minutes. She will next face former World No.1 Karolina Pliskova of the Czech Republic. The win over Garcia is Linette's fourth career top-10 victory, and all four of them have come at Grand Slams. Three of them have been over the top-5 opponents. "I still can't believe it. I don't know what happened. I'm speechless really. I don't want to say I didn't expect it, because coming on the court I was confident with how well I was playing, but she's such an amazing opponent and such a tough one, especially on a big stage. I'm just glad I stayed composed throughout the first set and managed to come back again," Linette said in her on-court interview. On the other hand, Pliskova extended her head-to-head dominance over Zhang Shuai of China to advance to her 11th career Grand Slam quarterfinal. The Czech's 6-0, 6-4 win in just 55 minutes improved her career record against Zhang to 8-0, and put her into the final eight of the Australian Open for the fourth time. The former No.1 came from 2-4 down in the second set but cruised against No.23 seed Zhang, who is a former Australian Open quarterfinalist. With the win, Pliskova improves to 11-3 in her career in Grand Slam fourth rounds, including 4-0 at the Australian Open. Pliskova is 7-2 in her career against Linette. They played twice last year, splitting those meetings. Pliskova won a thriller at the US Open in a third-set tiebreak, 6-2, 4-6, 7-6(8), but Linette got her revenge at the Billie Jean King Cup Finals in Glasgow in November with 6-4, 6-1 win. /IANS