Young tennis star Jones already scaring world's best

Russia's top-ranked player Daria Kasatkina rates rising Australian teen Emerson Jones a "scary" prospect as the exciting local talent builds towards her Australian Open debut.

Jones, who tops the junior girls' world rankings, pushed world No.9 Kasatkina all the way in their Adelaide International meeting on Wednesday night.

The 16-year-old from the Gold Coast won the first two games of the opening set without dropping a point, but was eventually beaten 7-5 6-3 by her vastly more experienced opponent.

Kasatkina, a French Open semi-finalist and Wimbledon quarter-finalist, then had her campaign abruptly ended in Thursday's quarter-final by a red hot Madison Keys.

"It was a pretty intense match," Kasatkina said after Wednesday's win.

"She's got really good tennis, so I'm already a bit scared, to be honest. She's just 16."

Jones has already drawn comparisons with three-time major champion Ash Barty and won plenty of admirers this week in Adelaide.

She banked her first win over a top-50 ranked player, sweeping aside China's world No.37 Wang Xinyu 6-4 6-0 in the opening round.

Kasatkina's push for a ninth career WTA title was snuffed out by the American world No.20 Keys, who won 6-1 6-3 in less than an hour to set up a semi-final date with Russia's world No.26 Liudmila Samsonova, who upset American second seed Emma Navarro 6-4 6-4. .

Kazakhstan's Yulia Putintseva then pulled off an epic late-night win 7-6 (7-3) 6-7 (9-11) 6-4 over Russian sixth seed Diana Shnaider, finally prevailing on her seventh match point, and will meet top seed Jessica Pegula in the other semi.

American world No.7 Pegula led compatriot Ashlyn Krueger 6-4 2-0 when her opponent retired because of injury.