A win each from Venus and Serena and we will get to witness another all-Williams final in a Grand Slam tournament.
Serena and Venus will play two outsiders in their respective semifinals, and if they stay true to form and play to their potential, we should have the two sisters clashing for the Australian Open women's singles title.
Having reached her first semifinal in Melbourne in 14 years, Venus will not want to stop at the last four. The veteran has looked in great form over the last 10 days and with the final now in sight, Venus will push for one more brilliant performance from that wonderful racquet of hers.
Standing in her way is Vandeweghe, who has beaten Roberta Vinci, Eugenie Bouchard, Angelique Kerber, the defending champion, and Garbine Muguruza on her way to the semifinals.
So, the fellow American is clearly not averse to knocking out big names, which means Venus will need to be at her best to make it to the final of the Australian Open.
"It's a great win for the US," Venus said of two Americans playing each other in the semifinal. "To have that thought that there's going to be at least one US player in the final is great for American tennis.
"I'm sure she's going to want to be in her first final. I'm going to want to be in only my second final here. So it's going to be a well-contested match."
Vandeweghe, having knocked out so many higher-ranked opponents already, will fancy one more scalp in the shape of the No.13 seed.
"To play an unbelievable player, future Hall of Famer, Venus, to be on the court with her, I've only experienced it one time before," Vandeweghe said. "But to do it at this stage of a Grand Slam is kind of crazy. I mean, I can't really put it into words."
The second match will be between Serena and fairytale semifinalist Mirjana Lucic-Baroni, who made it to the last four of a Grand Slam for the first time since 1999. This is a true battle of the golden oldies in terms of tennis age, with Serena at 35 and Lucic-Baroni aged 34.
"She's playing really well," Serena said of facing Lucic-Baroni. "I think it's so important not to underestimate anyone. This has been coming for her for a long time. She's been wanting to win Grand Slams and to do well.
"I think it's so important for me to just stay focused and hopefully play well. Hopefully I'll be able to get a win. I'm here to win. I'm here to do the best that I can. Yeah, so hopefully I'll be able to do well."
When to Watch Live
The first semifinal Venus vs Vandeweghe is set to begin at 2pm local time (8.30am IST, 3am GMT, 10pm ET), with the second one following after that.
Live Streaming and TV information:
USA: TV: ESPN 3. Live Streaming: Watch ESPN.
Australia: TV: Channel 7. Live Streaming: 7 Live.
UK: TV: EuroSport. Live Streaming: EuroSport Player.