The American, who tends to flourish on home soil, adapted considerably better than her opponent to the blustery conditions and enjoyed a trouble-free victory.
It’s the first time Stephens, a Florida native, has reached the last four of an event since her exploits at the US Open last September.
The 25-year-old is replicating the type of form that took her to Grand Slam glory – and she will not be daunted by the prospect of facing Victoria Azarenka for a spot in the final.
“It was uncomfortable” [playing in windy conditions], acknowledged Stephens. “You’ve got to get out of your comfort zone to get your best results. A little adversity never hurt anybody.
“I just played my game and had a good game-plan. I stuck to it the whole time and tried to execute it the best I could in the wind, and I just tried to stay as focused as I could be.”
Kerber squeezed beyond Yafan Wang after a near three-hour battle on Monday, and she looked to be feeling the effects of past exertions this afternoon.
It took the former world No.1 until the mid-way point of the second set to really rise to the challenge, however by that stage, the match was under the control of her rejuvenated opponent.
Kerber committed eight unforced-errors in the opening stanza, but it was her lack of aggression that contributed to the one-sided nature of the scoreline. She clubbed just one winner as her rival dictated matters from the baseline.
The German had a brief confab with her coach prior to the second set, and she was more energetic and vocal when play resumed. Stephens level of play remained high though, and she converted her sixth break-point in an elongated fifth game to move a step closer to her aim.
It was a knockout blow from Stephens’ perspective, and she did not concede another game as she laid down a marker to her competitors.
In the second quarter-final, Azarenka got the better of Karolina Pliskova 7-5 6-3 to remain on track for a fourth Miami Open crown.
“It feels really good,” said the former world No.1. “Before the match I said it was going to be a great test for me to see where my game is at. I think it gives me a lot of positive things to continue to work on.
“Seeing the progress that I made throughout this whole tournament, playing first round to playing a Top 5 player, I made a pretty good improvement – so I want to continue to go down this path.
“I think I'm not a bad player, so I know how to win matches. I have a lot of experience. For me it's important to stay healthy, to keep improving and to be able to play.”