Hull and Vu enter the final round in a share of the lead on nine-under-par after a pair of scintillating Saturdays at Walton Heath.
Six birdies – including three in a row from 15 – catapulted Hull up the leaderboard, but she is keeping at bay thoughts of winning her first major title.
“It would be unbelievable; it would be absolutely unbelievable,” said Hull, who finished in a tie for second place at the US Women’s Open in July.
“What Georgia [Hall] done in 2018; that was unbelievable. To do that again would be unreal. But [I will take it] one step at a time and just go out there and have fun.”
No player carded a lower third-round score than Vu’s five-under 67, which was supplemented by seven birdies.
“I think you're always nervous no matter what position you're in, because if you're leading, you kind of don't have the win yet,” said Vu, who won the Chevron Championship in April.
“You never really have it until the final round, 72nd hole and you're done with your putt.
“So I'm not going to be thinking too much about it. I'm just going to play my game.”
Kim certainly has form for carding low rounds in the main events as she set the record for men’s and women’s majors when she compiled a staggering 10-under-par 61 at the Evian Championship in 2014.
And it is the second major this year that Yin has been in contention on the final day, after losing a play-off to Vu at the Chevron.
“I think you're going to see a lot of aggressive and good golf [on Sunday],” predicted Yin, who matched Vu’s low score of 67 in round three.
“It's going to be great for the fans. The turnout this week is unbelievable, and as a golfer, you're appreciative of all the fans who come out. It’s so amazing to see.”
Ally Ewing held a five-shot lead coming into Saturday, but recorded six bogeys on a difficult afternoon for the American. She will begin her final round two strokes adrift.
Swedish star Linn Grant, who has won five times on the Ladies European Tour after just two years as a professional, is a shot further back after signing for a four-under 68.
Grant needed just 24 putts on Saturday, the lowest tally from any player in any round all week.
Aside from the pressure of Championship Sunday, the one major obstacle that leaders will need to navigate in the final round is the heather that furnishes the picturesque Walton Heath track.
A host of players have unwittingly found themselves caught up in purple peril following wayward tee shots across the first three days.
Finding fairways and greens is a common mantra in golf, but nowhere is it more pertinent than in Surrey on Sunday.