Aussie Open semifinal power rankings: It's Serena's to lose

— -- MELBOURNE, Australia -- The fortnight began with 256 hopefuls in the men's and women's singles draws, but we're down to the elite eight at the Australian Open.

Who will prevail in the 2017 season's first Grand Slam? Just between us, here's a cheat sheet, the ESPN.com celebrated Semifinal Power Rankings:

No. 8 Mirjana Lucic-Baroni: She hasn't been to a major semifinal in more than 17 years, but here is the 34-year-old Croatian in a truly unlikely spot. She was 1-8 in Australian Open play coming in, but she has won five straight here this fortnight. The real issue, though, is that tightly wrapped left thigh that sent her off the court at a pivotal moment in the third set of her quarterfinal win over Karolina Pliskova. It was a great run, but this is where she hits the wall.

No. 7 Grigor Dimitrov: The 25-year-old Bulgarian, once known as "Baby Fed," is into his second career Grand Slam semifinal, matching a stellar effort at Wimbledon in 2014, when he beat Andy Murray in the quarterfinals but lost to eventual champion Novak Djokovic. This time, Dimitrov had to get by David Goffin in the quarters and Denis Istomin -- who took the No. 2-seeded Djokovic out of the tournament -- before that. Dimitrov is smooth, as the nickname suggests, but odds are he won't advance to his first career major final.

No. 6 Venus Williams: Somehow, she's still rising. Williams, the oldest female Grand Slam semifinalist in the 49-year history of the Open era, hasn't acted her age -- which is 36. Venus hasn't dropped a set in five matches and finds herself in the final four here for the first time in 14 years. Beating the red-hot Coco Vandeweghe, however, is a big ask.

No. 5 Coco Vandeweghe: She described herself as a runaway freight train, and that's just about right. Vandeweghe, a confident Californian, has erased, in order, Eugenie Bouchard, No. 1-ranked Angelique Kerber and reigning French Open champion Garbine Muguruza. Why not Venus Williams?

No. 4 Stan Wawrinka: Sure, the three-time Grand Slam champion has lost 18 of 21 matches to his Swiss Davis Cup partner, but over the past three years, the record is a more manageable 2-5. Wawrinka won the last Slam contested, the 2016 US Open, and has been playing with great confidence. Here's his take on Roger Federer: "He's the best player of all time. He has answer for everything. But I managed to beat him in a Grand Slam [the 2015 Roland Garros quarterfinals], so we'll see."

No. 3 Rafael Nadal: Lost in the comeback of the 35-year-old Federer is the resurgence of 30-year-old Rafa. He hadn't been in the past 10 major semifinals, but here he is after beating Milos Raonic. He looks like a lock against No. 11 seed Dimitrov, who is a now a two-time Slam semifinalist. Rafa? He's been to 24.

No. 2 Roger Federer: He came in as a 21-to-1 long shot and now he's favored by oddsmakers to win his 18th Grand Slam singles title, the first in more than four years. After a six-month sabbatical, Federer finds himself in a good place -- his 13th semifinal here in 14 years. Federer has dominated the "Stanimal" -- it's an astonishing 18-3 head-to-head.

No. 1 Serena Williams: No one has played better here. She beat No. 9 seed Johanna Konta 6-2, 6-3 -- in a scant 75 minutes. And despite issues with her first serve (missing 55 percent of them), she managed to win 23 of those 26 points. Her opponent in the semifinals (see No. 8) is injured and looks very beatable.