Lindley shot an 8-under-par 64 over the New Albany Country Club, and leads by one shot over Wendy Ward, who went around in a fine 65 herself.
The 29-year-olds round ousts her previous best of 65, which she shot most recently at the 2000 First Union Betsy King Classic.
It also sees her two strokes ahead eight others at 6-under, including big names Michelle McGann and Rosie Jones, while Karrie Webb and Annika Sorenstam each shot 67 on Friday to be three back at 5-under.
Despite all the stars in the mix, however, the day belonged to the unheralded Lindley.
The South Florida resident made no mistake of her intentions, as she birdied an incredible seven of her first nine holes, and then added a final red number at the par-4 12th to take outright control at 8-under.
Click here for Leta Lindley's scorecard.
The only holes Lindley did not birdie on the front nine were Nos. 1 and 5.
Everything else was perfection.
Yet in six full years on the LPGA Tour, Lindley has yet to find perfection, as she has not yet won.
On two occasions (1997 and 1999), she has finished second in an event, but is in prime position entering the weekend for her first.
She will have to deal with the ever-present figures of Sorenstam and Webb, however.
Winners of three of the four majors in the 2001 season, the International duo made just three bogies between them on Friday, and are each looking for their first wins since making LPGA television-history at last months Battle at Bighorn, when they partnered with Tiger Woods and David Duval in front of a prime time audience.
Full-field scores from the Wendy's Championship for Children