Bourdy, who shared the lead after the first round, had an up-and-down round Friday that included an eagle and six birdies. He finished at 5-under-par 67 and moved to 12-under 132 for the tournament.
Mark Foster matched Bourdy's 65 with a bogey-free round and is at 11-under after 36 holes. Three players, including Paul Waring, who fired 7-under 65 Friday, are tied for third at 10-under.
Also in third place are Lorenzo Gagli, who had a second-round 66 and Padraig Harrington, with a 67 Friday.
First-round co-leader Jeev Milkha Singh turned in a 1-under 71 in the second round and is tied for eighth at 8-under.
Bourdy started hot Friday with an eagle at the par-5, 528-yard second hole and a birdie at the par-3 third before his first bogey of the tournament at No. 4. He then had four birdies in a five-hole span. Bogies at 11 and 14 slowed him some but he had a 4 at the par-5 17th for his 67.