Kenin had reached a career-high number four in the world rankings after her 2020 Melbourne triumph and finished runner-up at the French Open later that season, before injuries, illness and off-court issues saw her drop to 235 last year.
But the resurgent American has battled her way back to 53 in the world and is now seeking a first trophy of the season and sixth overall having lost in three sets to Barbora Krejcikova in the final of the San Diego Open last week.
"I'm very happy, very proud of myself," said Kenin, who is bidding to make her first WTA 1000 final. "Obviously it means a lot to me. I've been putting in some hard work and it's paying off, so I'm super proud.
"Of course, confidence with the matches I'm playing, wins in a row. Confidence definitely is the key for me."
In the semi-finals, Kenin will take on American world number 111 Caroline Dolehide who saved four matchpoints to beat Martina Trevisan 3-6 7-6(9) 6-3.
"To be honest, I had to find a way today to win," Dolehide said after reaching her first Tour-level semi-final. "When I was down those matchpoints, I told myself 'Do what you practice', which my coach tells me every single day of my life.
"I just played with my kick, played with my best shots and I ended up winning that set. It gave me a lot of confidence going into the third."
Earlier, third seed Caroline Garcia powered past two-times Grand Slam champion Victoria Azarenka 6-3 6-4.
"It's always tricky," said Garcia, who saved all 11 breakpoints she faced to reach her first semi-final since March. "She had a lot of breakpoint opportunities, but I served really well at those points, so I guess I have to thank my serve."
The Frenchwoman meets second seed and last year's runner-up Maria Sakkari, who eased past Emiliana Arango 6-3 6-4.
