Feng’s 4-under-par 67 Saturday put her out front in Waterloo, Ontario, Canada.
At 15-under 198, Feng is two shots ahead of Wie (68) and Park (65). She’s three ahead of Kerr (65).
Ko soared up the leaderboard Saturday with a 64, the day’s low round, giving her a chance to become the youngest Rolex No. 1 in the history of the women's game. She moved four shots off the lead and needs to win to have a chance to overtake Stacy Lewis as the new No. 1.
Nordqvist (69), seeking to become the first three-time winner this LPGA season, is also four shots back.
Wie kept herself in the hunt despite a rough start. She bogeyed two of the first three holes to fall off the pace but rallied with six birdies and a bogey the rest of the way.
“Quite a shaky start,” Wie told reporters after her round. “I missed a good birdie opportunity on the first hole, and then I kind of duck-hooked it on the second hole and had to take an unplayable. Actually, it was a really good bogey. Then I kind of hooked it on the next hole, hit it in the bunker. So I just couldn't get my tempo right in the beginning, but definitely felt like I finished strong.”
That kind of start might have derailed Wie a year ago, when she ranked No. 100 in the world. With five finishes of fourth place or better this year, including her victory at the Lotte Championship, her first title in four years, Wie’s confidence is high. She joked after the third round that she was more upset about breaking a nail than she was about the early bogeys. She has climbed to No. 10 in the world with the kind of resilience she showed after Saturday’s rough start.
“I’m getting more and more confident,” Wie said. “But it's always a work in progress, because golf is such a finicky game. It's like, one day you're feeling really great, the next day you're not.”
Feng is looking for her fourth LPGA title.
“I’ve had no pressure this week,” Feng said. “Last year, I missed the cut here, so I came just to have fun.”
Feng, Wie and Park will be in the final group Sunday.
Park got herself in position to claim her first LPGA title since winning the U.S. Women’s Open almost a year ago. She would love to go to Pinehurst No. 2 in eight days to defend her title coming off a victory.
“The first win is always very important, and that would give me a lot of confidence going into the U.S. Open, that's for sure,” Park said. “So, yeah, that's going to help a lot.”
Park saw her 59-week reign atop the Rolex Women’s World Rankings end last week, when Lewis overtook her with a victory at the ShopRite Classic. Park can’t gain her No. 1 ranking back with a victory Sunday, but Rolex world No. 3 Ko can get there.
If Ko wins, and Lewis finishes eighth or worse, Ko will head to the U.S. Women’s Open as the youngest No. 1 in the history of professional golf. Ko's small divisor, with fewer starts than Park, enables her to make the rankings jump to No. 1 with a win.
Lewis starts Sunday tied for 18th, eight shots back.
“You never know what's going to happen,” Ko said.