The top-seeded Jones fought back from a set down to defeat Austrian Lilli Tagger 4-6 6-2 6-2 on Thursday, remaining on track to become the first Australian since Siobhan Drake-Brockman in 1995 to win the girls title at Melbourne Park.
Emerson Jones during her Australian Open junior girls' quarter-final win on Thursday. (James Ross/AAP PHOTOS)
She then backed up on Thursday night to surge into the girls doubles semi-finals, partnering Great Britain's Hannah Klugman.
Runner-up in both the Australian Open and Wimbledon girls finals last year, Jones is the world's top-ranked junior and already drawing comparisons to retired great Ash Barty.
The teenager will face Japan's Wakana Sonobe after the fourth seed overcame another Australian, Tahlia Kokkinis, 6-2 6-4 in their quarter-final later on Thursday.
Queenslander Tahlia Kokkinis has fallen at the quarter-final stage of the girls tournament. (Joel Carrett/AAP PHOTOS)
Queensland 16-year-old Kokkinis, who was handed a wildcard entry, was unable to keep her giant-killing streak going.
After being outplayed in the first set, Kokkinis broke her more fancied rival to take a 4-2 lead in the second.
But a medical time-out interrupted her flow and Sonobe struck back, breaking the home hope's serve to level at 4-4 and then again to wrap up the victory.
In the girls doubles, second seeds Jones and Klugman downed Czech duo Tereza Krejcova and Vendula Valdmannova 7-6 (7-3) 6-3.
They will take on American identical twins Annika and Kristina Penickova, who are the sixth seeds.
The 15-year-old twins overcame another sister combination in Czech pair Alena and Jana Kovackova.
Kristina Penickova is also into the final four of the girls singles and will face Slovakia's Mia Pohankova.
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