Over the past 12 months, Sloane Stephens' ranking has zig-zagged from No. 25 to No. 957 to No. 83. Her gradual drop is not uncommon for someone missing almost a year through injury. Her sudden rise is almost unprecedented. It's peaks and valleys on an almost superlative scale. 

Barely able to walk four months ago, Stephens is now into her first-ever Grand Slam final – just her fifth tournament of the year after undergoing surgery on her left foot in January.

With her US Open semifinal win over Venus Williams inside Arthur Ashe Stadium on Thursday night, Stephens is now guaranteed to be at least No. 22 when the new rankings are released on Monday. That's a rise of more than 900 spots in a little more than five weeks. 

It's a remarkable recovery for the former world No. 11, who often joked about having a "peg leg" for many months, when she was unable to put weight on her foot.

Stephens is just the 14th unseeded woman to advance to a Grand Slam final in the 50-year history of the Open era and only the fourth woman to accomplish the feat at the US Open, behind Venus (1997), Kim Clijsters (2009) and Roberta Vinci (2015). Stephens was the seventh player ranked outside the Top 50 to advance to the US Open semifinals since rankings began. Of those, only Clijsters, who came out of retirement after giving birth to her first child, raised the trophy. 

Now, the 24-year-old is one win away from the biggest victory of her own career, an achievement that would replicate Clijsters' historic, unlikely win

Here's a look at Stephens' timeline as she's returned from injury.

Aug. 6, 2016
Rank: 28
Stephens loses in the first round of the Rio Olympics to Canada's Eugenie Bouchard. The American says she had a stress reaction in her foot, the precursor to a stress fracture, where the bone is becoming weaker.

Aug. 26, 2016
Rank: 25
Stephens officially withdraws from the 2016 US Open with a foot injury. She had played in every Grand Slam tournament since the 2011 US Open and would have been seeded in Flushing Meadows. Doctors advise her to wear a protective boot over the fall and winter. She wears the boot for 15 weeks before starting her preseason training.

Jan. 8, 2017
Rank: 35
Stephens travels to Sydney for an Australian Open tune-up event but pulls out before the start of the tournament after feeling further discomfort in her ankle. 

Jan. 23, 2017
Rank: 49
Having traveled back to the U.S. to see a specialist, Stephens undergoes surgeryon her foot after an MRI revelas a stress fracture in her left navicular, a bone near the ankle.

Feb 10. 2017
Rank: 52
Stephens shares a photo of her with a protective boot on her left foot on her Instagram page and says she'll be out of action for several months, with the target of a summer return. She starts contributing to the Tennis Channel's TV coverage, sharing firsthand insights of life on the WTA tour.

April 18, 2017
Rank: 158
With outstretched arms and a little wobble, Stephens takes her first tentative steps since the surgery. Unable to defend the points she has earned over the past 12 months, Stephens slips outside the Top 100 in the rankings for the first time since October 2011. 

 

play video Performance of the Day: Sloane Stephens

April 26, 2017
Rank: 158
Stephens is back out on the tennis court, although not in a way you would normally see her. Sat in a folding chair just behind the service line, she starts hitting gentle forehands as her coach feeds underhand tosses from a few feet away.

May 5, 2017
Rank: 158
Stephens shares a video on Twitter of her jogging on an anti-gravity treadmill as part of her rehab. By utilizing the machine, she can rehabilitate without putting her entire body weight on her foot and ankle as she runs.

July 4, 2017
Rank: 336
Playing her first match since the surgery, Stephens falls to fellow American Alison Riske, 6-2, 7-5, in the first round of Wimbledon. The timeline worked out perfectly for Stephens, whose doctor said she she could play tournaments six weeks after she started training.

July 16, 2017
Rank: 901
On Court 17 at the USTA Billie Jean King National Tennis Center, Stephens and fellow American Taylor Townsend team up to play doubles for the Philadelphia Freedoms against the New York Empire in Mylan World TeamTennis.

Aug. 1, 2017
Rank: 957
Stephens slips to a career-low No. 957 in the rankings. She accepts a wild card into the Citi Open in Washington, D.C. but falls to top seed Simona Halep, 7-6, 6-0, in the first round. She earns one ranking point, enough to climb 23 places. 

Aug. 7, 2017
Rank: 934
Stephens wins her first match since July 1, 2016, rallying to beat Yulia Putintseva, 6-7, 6-0, 6-4, in the first round of the Rogers Cup. She goes on to beat world No. 14 Petra Kvitova, reigning US Open champion and world No. 3 Angelique Kerber and No. 41 Lucie Safarova before eventually falling to sixth-seeded Caroline Wozniakci in the semifinals. She earned 350 points to jump almost 800 places, to No. 151.

Aug. 19, 2017
Rank: 151
The 24-year-old records consecutive semifinal appearances for the first time since 2013 (Hobart and Australian Open). The wild card beat four Top 50 players on her road to the final four, where she loses to Halep. But 350 more points sees her climb back inside the Top 100 for the first time since April 2017.

Aug. 28, 2017
Rank: 83
Using her protected ranking, Stephens enters the US Open and beats Roberta Vinci in the first round. It was her first win in New York since beating Annika Beck in the first round three years ago. Victories over No. 11 seed Dominika Cibulkova, Ashleigh Barty, No. 30 seed Julia Goerges, No.16 seed Anastasija Sevastova and seven-time major champion Venus Williams sees Stephens advance to her first Grand Slam final.

Sept. 7, 2017
Rank: 83 (provisionally 22)
With her semifinal win over Venus, Stephens will climb to at least No. 22 when the new rankings are released on Monday. It will be the first time she has been ranked that high since June 2016. If Stephens wins on Saturday, she will climb to 15th in the world, her highest ranking since January 2014.