Bradley followed up his course-record 60 with a 1-under 69 on Friday.
Bae recorded a second consecutive 66 and is 8-under. Gillis, seeking his first PGA Tour title, fired a 63 in the morning wave.
Area resident John Huh shot 64 in the morning and was one of three players tied at 7-under, joining Charl Schwartzel and Ryan Palmer. A host of players, including Angel Cabrera, are another shot back at 6-under.
Among players who missed the cut and won't be around for the weekend is 14-year Chinese prodigy Guan Tianlang, who shot 77 on Friday after opening with a 70.