Players aimed straight at the pins for a third straight day and the scoreboard was loaded with low scores as a result.
South Korea's Hee Young Park shot a career-low 61 to move into sole possession of top spot at Grey Silo Golf Course. Her 20-under-par 193 total left her one shot up on American Angela Stanford and two strokes ahead of Scotland's Catriona Matthew.
With 21 players already in double digits at 10 under or better and course conditions likely to stay the same, expect a shootout on Sunday.
"When you see everybody going low, you have to go with them or you're going to get left behind," Stanford said.
Park's three-round score was the best 54-hole total on tour this year and it was just the 11th time a play has shot 61 in tour history. She almost went one better — nearly chipping in for eagle on the 18th before tapping in a short putt for her sixth birdie on the back nine alone.
"I finished really well, finished (with) the birdie, so it's going to be fun tomorrow," she said.
Matthew (68) started the day with a three-shot lead on Stanford (64) but fell back with a double-bogey on the par-3 12th hole. She followed with a birdie and got another stroke back with a birdie on the final hole.
"Yeah, didn't maybe click quite as well today, didn't hit it quite as close," Matthew said. "Had a lot of chances but just kind of left a few, and then a silly double on 12, kind of getting a bit greedy going for the hole and just pulled it.
"Nice to come back with a couple birdies."
Meena Lee of South Korea was three shots off the lead after a 65, while Sweden's Anna Nordqvist shot a 67 and was five shots off the pace.
South Korea's Inbee Park remained in contention after a 67, good for a ninth-place tie at 13 under. Park has won her last three tournaments.
"I had a lot of opportunities today but missed a lot of putts," she said. "I mean I hit the ball the way I wanted to, that's the positive part to take away. Hopefully the putts will go in tomorrow."
Lorena Ochoa was the last player to win four straight LPGA tournaments, accomplishing the feat in 2008. Nancy Lopez holds the tour record with five consecutive wins in 1978, a mark equalled by Annika Sorenstam over the 2004-05 seasons.
The sunny, warm and breezy conditions held steady throughout the day on the 6,330-yard par-71 course. American Gerina Piller got things started early in the afternoon with a 62, taking a stroke off the competitive course record.
Her mark lasted for about two hours.
Park hit a slick four-foot tester for the 61 as the gallery roared its approval. She smiled, waved and tossed the souvenir ball into the grandstand.
"It's anyone's game," Piller said. "Like today if you get someone that gets hot with their putter and I mean, it's a free for all. The course is in great condition.
"Like I said the greens are soft, so that's kind of a green light for us as pros that we can just kind of throw darts and it makes it a whole lot easier."
Jennifer Kirby (69) of Paris, Ont., was the top Canadian at 7 under. Charlottetown's Lorie Kane (70) and Brooke Henderson (71) of Smiths Falls, Ont., were next at 6 under and Hamilton's Alena Sharp (69) was at 5 under.
Matthew said she believed anyone within seven strokes of the lead might have a chance on Sunday.
Stanford, meanwhile, had predicted earlier in the tournament that the winning score would be in the 20-under range. Now she thinks 25 strokes under par might be needed.
"We see a couple courses throughout the year that give up some birdies, but they're the best players in the world and if you give them soft greens, it's like letting, what, the kid go after candy," she said.
Notes: The tournament purse is US$1.3 million. ... Sorenstam became the first LPGA Tour player to shoot 59 back in 2001 at a tour event in Phoenix. A score of 60 has been recorded on only four occasions, according to a tour spokesman. ... Nordqvist shot a 61 earlier this season at the LPGA Mobile Bay Classic last May. ... Warm and mostly sunny conditions are expected again Sunday although there is a chance of thunderstorms.