Scott Stallings fired a brilliant 11-under 60 to take a one-shot lead at the Barbasol Championship on Saturday.
The American made 10 birdies - including on the final three holes - an eagle and a bogey during his third round in Opelika, Alabama.
Stallings' round saw him move to 19 under, enough to be ahead of Grayson Murray (64).
Tag Ridings (63) and Chad Collins (69) are tied for third at 17 under, while Cameron Tringale (67) is two shots further back.
Stallings' 60 was the second in as many days at the PGA Tour event, with Collins having also achieved the feat - a course record.
Ben Martin (64), Cameron Percy (65), Sam Burns (66), Shawn Stefani (66), Robert Garrigus (66) and Brian Gay (68) are at 13 under.