The pair, atop at the leaderboard at 19-under 125, got hot on the back nine to move up and post a one-stroke advantage over first-round leaders Mark O'Meara and Nick Price (64) as well as the team of Blaine McCallister and Bob Tway (63).
Bean holed out from the 10th fairway using a nine-iron, notching an eagle, while Lu birdied a 10-foot putt on 11, followed by a 40-foot birdie putt on the 12th hole.
Lu got another birdie on 13, and then on the 15th hole Bean got within a foot of the cup and tapped it in for a fourth straight birdie. Lu birdied the par-3 15th while Bean connected on a 15-foot birdie putt on 16 and a 6-footer for birdie at No. 17.
Co-first round leaders John Cook and Joey Sindela fired a 7-under 65 Saturday, good for sole possession of fourth place at minus-17.