The US 13th seed’s comprehensive triumph in tricky wind conditions over the former world number one ensured Stephens reached the last four at Key Biscayne for the first time.
It also means the reigning US Open champion will finally be named in the world’s top 10 when the WTA release their rankings next week.
She will meet two-time Australian Open champion Azarenka for a place in Saturday’s final after the Belarusian beat fifth-seeded Karolina Pliskova 7-5, 6-3.
“I am so tired of hearing that I am number 11 in the world,” said a smiling Stephens.
“It’s very exciting to get there, something I have wanted to do for a while. Getting into the top 10 is pretty special and something I have worked on for a long time.”
Azarenka, meanwhile, is enjoying her best tournament run since the birth of her first child in December of 2016 and faces Stephens just three weeks after the pair met in Indian Wells, a match won by the American 6-1, 7-5.
In an error strewn clash with world number six Pliskova, Azarenka , who was given a wildcard into the tournament thanks to a ranking of 186, was broken when serving for the first set only to break back straight away and take control.
The pattern continued at the start of the second, yet the 28-year-old held her nerve to reach the last four of a tournament she won in 2009, 2011 and 2016 and complete a return to the top 100 when the WTA rankings are updated this Monday.
“Every match is important right now, I hope it’s a different story from last time we met,” Azarenka said. “I don’t want to take anything from that match because it was terrible although I did have opportunities but I didn’t take them.
“The possibility of winning (the tournament) is always in my head,but I need to take it one match at a time,” she added. “I know there is a long way to go before winning the final.”
Azarenka’s return from the birth of her son has been complicated by a custody battle that limited her ability to travel, but she said physically she is firing on all cylinders.
“I have surprised myself with the transformation I have achieved since coming back from pregnancy,” she said. “I have actually got in better shape which can be unusual for a woman. I feel physically well, I want to get faster and stronger but I am in good shape. I just need to keep working to get tournament fit.”
Stephens’ previous best in Miami came with a quarter-final run in 2015, so the emotions on display at the end of what was an ultimately straightforward win over the world number 10 were understandable.
Since her debut Grand Slam triumph at the US Open last September, the 25-year-old has struggled to follow on. Stephens arrived at Key Biscayne having not beaten a top-50 player since the run at Flushing Meadows.
But this week has seen the American, who was raised in South Florida, get back to her roots — and to winning ways.
Reigning Wimbledon champion Garbine Muguruza was emphatically dispatched in straight sets Monday before Kerber received similar treatment.
Wind hampered both players, but it was Stephens who adapted far better — the power of her groundstrokes and superior movement leaving Kerber frustrated and unable to find a way into the encounter.
“The wind is uncomfortable for both of us. But it can help push you outside of your comfort zone. You just have to embrace it,” Stephens said.
‘Stick with it’
Stephens took just 23 minutes to wrap up the first set as Kerber looked sluggish from the start.
Kerber was deep in conversation with coach Wim Fissette during the break, being urged to assert herself.
Kerber saved four break points in the fifth game but Stephens was did not allow her opponent into the match and a 22nd winner sealed the triumph.
“You have to execute your game well and make sure you stick with it,” Stephens said. “It’s easy to start doing other things so I just need to keep to my plan and make sure I didn’t venture off.”
Kerber admitted coming through a grueling three-set win over qualifier Wang Yafan the day before had left her flat.
“I was really feeling a little bit tired today,” Kerber said. “It was windy, it was tricky, but I’ve played so many matches in the last three months that I was feeling it a little bit in my body.” —AFP