But Aussie two-time major champion Minjee Lee was unable to take advantage.

Lee's hopes of a third major all but disappeared as a third-round three over 75 on a windy Saturday afternoon pushed her in the wrong direction on moving day as she slumped to nine shots in arrears of the nine under clubhouse lead held by Hull and Vu.

But the Perth star's slump didn't match the disappointment for American Ewing, who began the day five shots clear but ended it two shots off the lead after her own 75 featured six bogeys and quickly opened the door for a crew of distant pursuers.

Hull finished strong with three birdies over the final four holes for a 68, raising hopes of a first home winner of the Open since Georgia Hall's victory at Royal Lytham five years ago, while Ewing's compatriot Vu became the leading U.S hope as she carded seven birdies and two bogeys for a 67.

"It would be absolutely unbelievable," Hull said, when asked about the prospect of winning.

"What Georgia did was unbelievable and to do that again would be unreal. But one step at a time and just go out there and have fun."

Charley Hull plays from the heather on the 18th hole but was still able to escape with par. PHOTO: Getty Images.

Vu, who won the Chevron Championship in April, now has the chance of her second major triumph of the year. No American has achieved that feat since Juli Inkster in 1999.

Another American Angel Yin and South Korean Kim Hyo-joo were one stroke back in joint-third, with Ewing down to fifth place going into Sunday.

FINAL ROUND TEE TIMES (AEST) & PAIRINGS

Not that she has given up the ghost yet. Far from it.

"I didn't execute shots quite like I wanted to early on, but I fought really hard today, and you know I'm teeing it up tomorrow with still a great chance to win this golf tournament," she said.

"Obviously the situation was tough, coming out with pretty windy conditions.

"It took me a little bit longer than I would have liked to settle in. The nerves were obviously there but, at the same time, I was mentally in a good place to know that I was going to be presented with challenges."

MInjee Lee never recovered from a slow start that included bogeys on three of the first four holes. PHOTO: Getty Images.

Lee's hopes were effectively sunk after she bogeyed three of the first four holes before dropping another shot just before the turn, and her revival on the home stretch wasn't enough to leave her any better positioned than joint-28th.

The other Australian to make the weekend, Sydney's Grace Kim, was a shot behind Lee on one over for the tournament after she carded a two over 74.

Other luminaries made better progress with World No.1 Nelly Korda shooting a 69 to move up to four under, five off the pace.

"I started off pretty well and then on the back nine, I just kind of started making more mistakes with the short stick," said Korda, who was on course record pace after an eagle on the par-5 11th moved her to five under for the round before losing that momentum with consecutive bogeys a few holes later..

"I'll head to the putting green and try to figure it out again. But overall, I would say I moved up on moving day, and conditions were tough - and I'll take that."

But French star Celine Boutier, aiming for a third consecutive win following her triumphs at the Scottish Open and the Evian Championship, ended at three over after a 74, her hopes over.

– Ian Chadband, with additional reporting from agencies