Bryant carded 10 birdies and didn't register a bogey during the exceptional round at En-Joie Golf Course, which the 50-year-old is hoping to translate Sunday into his first triumph on the seniors circuit.
He stood at 16-under 128, four better than Corey Pavin, who shot a 64 Saturday.
Duffy Waldorf carded a 65 to claim third place at minus-11, while Rick Fehr (67) and Russ Cochran (67) shared fourth at 10-under.
Rod Spittle (66), Gene Sauers (66) and Esteban Toledo (68) ended 32 holes knotted for sixth at minus-9.
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