Hannah Green is just two back while Lucas Herbert will have to chase down Rory McIlroy as the Aussie pair moved into position to push for drought-breaking wins.
Without a win on the LPGA Tour since her Portland Classic triumph three years ago, Green is tied for fourth through two rounds at Columbia Edgewater Country Club.
The 25-year-old did move to within one of the 10-under lead shared by Germany’s Esther Henseleit and American Lilia Vu but a bogey at the par-4 ninth – the final hole of her second round – resulted in a two-under par 70 and eight-under total.
Due to return home to Perth at the end of the week, Green began her second round with a birdie at 10 followed by eight straight pars.
She reached eight-under with a birdie at one but gave it back at the very next hole.
The TPS Murray River champion hit 13 of 18 greens in regulation and needed 29 putts to keep her hopes of a second Portland Classic title well and truly alive.
“I briefly saw a leaderboard on eight green that I was two back and that a couple of rookies that are up there,” Green said.
“It’s tough to win a golf tournament and I’m sure the course is just going to get harder come the weekend.
“Hopefully just keep posting low numbers and try and get into the last group on Sunday.”
Herbert has put himself in position for his best result in almost a year with a superb second round at the DS Automobiles Italian Open.
Only six players bettered Herbert’s four-under 67 on Friday, the 26-year-old moving into a share of fifth place and four shots from the lead at the halfway point.
A two-time winner on the DP World Tour, Herbert has not logged a top-five finish since his maiden PGA TOUR title last October.
In six starts since the Irish Open he has had three top-15 finishes and three missed cuts and was bitterly disappointed to recently miss out on Presidents Cup selection.
Locked in for a return home this summer, Herbert made his move on Friday on the back nine at Marco Simone Golf Club in Rome.
Making the turn in one-under, Herbert peeled off four birdies in the space of five holes from the par-5 12th where he got up and down from the right side of the green.
He backed that up with a birdie from inside eight feet at the par-3 13th and made putts from nine and five feet respectively at the par-4 15th and 16th holes.
Jason Scrivener’s second straight 70 puts him in a tie for 27th while an eagle and two birdies in succession moved Maverick Antcliff (69) safely inside the cut-line.
A bogey-free 68 has moved South Australian Adam Bland inside the top 30 at the Japan Golf Tour’s ANA Open and Cameron Percy (68) and Aaron Baddeley (69) advanced to the weekend at the PGA TOUR Fortinet Championship.
After making 18 straight pars in his debut round on the PGA TOUR on Thursday, Harrison Endycott began his second round with three straight birdies but it was the shot he picked up on his final hole of the day that ensured he made the cut in his first start.