The US Open champion was trailing the former world No.1 by a set and a break before she went on the rampage – winning 10 games in succession to effectively seal victory.
It was an impressive response from Stephens after a difficult opening, and she continues to flourish on home soil.
In the last 12 months, the 25-year-old has won 23 of 28 matches in the United States, which is in sharp contrast to her dismal form in the rest of the world.
After a challenging few years, for varying reasons, Azarenka will be encouraged by her performances and results at a tournament that has served her so well.
The Belarusian’s lack of court-time counted against her in the second half of the contest – she struggled with cramp – but that will only improve with more matches.
Due to her exploits in Indian Wells and Miami, Azarenka will be rewarded with a spot inside the Top 100 when the ranking are updated on Monday.
Azarenka was the more assured performer in the early stages and the depth on her groundstrokes greatly troubled her rival. Stephens was unsure how to combat her rival’s precise hitting, and quickly fell 3-0 behind.
Stephens eventually showed that type of form that helped earn her a spot in the last four – and Azarenka’s lead evaporated as a consequence. Locked at three apiece, the set was up for grabs, and it was the three-time winner that pulled away.
The Belarusian’s world-class backhand is a delight to watch in full flow, and it was firing on all cylinders as she took the opening gambit by six games to three.
Matters got decidedly worse for Stephens in the second set. The home-favourite trailed 2-0 and was heading rapidly towards the exit, however she showed true grit and clawed her way back into contention.
The American’s forehand rose to prominence and she forced her opponent to retreat. Stephens’ level had improved considerably, and it coincided with Azarenka’s dramatic dip in performance.
The US Open champion won six games in a row to take the set from her shell-shocked rival and force a decider.
Azarenka tried to muster a response in the final set, but her body did little to aid her cause. The 28-year-old was untidy from the baseline as fatigue became a factor, and an ankle issue impeded her movement.
Victory had looked so far away for Stephens in the early stages of the second set, yet she managed to win with plenty to spare. She can now rest and recuperate while Danielle Collins and Jelena Ostapenko battle it out in the second semi-final later tonight.