Creamer shot a 6-under 66 to move to 16-under-par 200 for the tournament, which is good for a one-stroke lead at Tartan Fields Golf Club. The 19-year-old rookie is in position for her third victory this year.
Cristie Kerr also fired a 66 in her third round to share second place. She and overnight co-leader Soo-Yun Kang, who shot a 69, are knotted at 15-under-par 201. Pat Hurst (67) and Michele Redman (68) are one stroke further back in a tie for fourth.
All in all there are 19 golfers within six strokes of Creamer heading into the final round, including Annika Sorenstam, who shares 11th place with six others at minus-11. Sorenstam, who is in action for the first time since the Women's British Open last month, shot a 3-under 69 in the third round.
The players sat through a three-hour rain delay in the afternoon, but Sunday's forecast looks good for those in position to catch Creamer.
'She has a lot of experience for her young age, but she's still young. There are going to be a lot of players coming at her tomorrow,' Kerr said of the leader. 'Hopefully, I'll be one of those.'
Creamer's bogeys at the 17th and 18th were her first since the opening round and cost her a three-stroke lead. But as much as they robbed her of what could have been a second straight bogey-free round, they did not detract from what was still a very strong round for the Evian Masters champion.
'It's not going to taste as good as it would if that didn't happen,' admitted Creamer, who has earned more than $1 million this season to all but lock up Rookie of the Year honors. 'Tomorrow is a new day, a lot golf left and hopefully I can keep playing the way I've been playing.'
Creamer opened her round on fire, stringing together three straight birdies after teeing off in the second-to-last group off the first tee. She hit a pitching wedge to within 6 feet at the first hole, knocked the same club within a foot at the second, and then set up a 20-foot birdie putt with her nine iron at No. 3.
That moved Creamer to minus-13, and things would only get better on the front nine.
After collecting a par at the fourth -- which she had bogeyed on Day 1 -- Creamer came right back with her fourth birdie of the round at No. 5 when she landed her pitching wedge within 7 feet. She went out at 15-under after a birdie at the par-4 seventh and consecutive pars to finish the front nine.
Two more birdies at the 11th and 12th -- she knocked wedges inside 10 feet on both holes -- put Creamer at 17 under. She moved further under par with her eighth birdie of the day at 16 before the disastrous finish.
At the 136-yard par-3 17th, Creamer blasted an 8-iron long and chipped within 15 feet before two-putting. She then three-putted at the par-4 18th for her second straight bogey, missing a 4-foot par putt that would have given her a two-stroke lead.
Creamer acknowledged that the bad weather played a negative role in her finish.
'The whole day just took so long out there, either we were behind or we were waiting,' she said. 'It was never a consistent, flowing round, so I think that definitely got to me a little after a couple of holes.'
Six-time major winner Karrie Webb (70) shares sixth place with Lorena Ochoa (67) and Amy Hung (68) at 13-under-par 203.
Sophie Gustafson and Laura Davies are knotted one stroke further back in ninth place after two spectacular rounds. Davies fired a 63 and Gustafson carded a 64, the two low rounds of the day.
Defending champion Catriona Matthew, who shared the overnight lead with Kang, struggled to a 5-over 77. She dropped into a tie for 33rd place at minus-7 with seven other golfers, including Monday qualifier Lara Tadiotto (69).