Sean Murphy remained in second place after a 1-under 70, which moved him to 7-under-par 206. Zach Johnson, David McKenzie and overnight leader Anthony Rodriguez are tied for third place at 6-under-par 207.
Ogilvie opened with a birdie at the par-5 first on the East Course at the Country Club of Hershey. He later rolled in back-to-back birdies from the sixth to move to minus-7.
'This is the first time I've played well here,' Ogilvie said. 'This is a great test to see how your game is. You've got to make pars. You've got to stay patient.'
Around the turn, Ogilvie climbed to 8-under with a birdie at No. 10. He continued his charge with a birdie on the par-4 12th. After making a great up-and-down par on 13, the Australian came back to birdie the par-5 14th.
'I was lucky enough that it was so far left it went past the trees,' said Ogilvie of his tee shot on No. 13.
After knocking his second over some trees and onto the green, he drained the par-saving putt.
'When that one went on, I figured to myself this is really a good day,' said Ogilvie.
That momentum was short-lived, however. He stumbled to a bogey at the par-four 15th, meaning his lead would be two instead of three heading to the final round.
'I like being ahead,' said Ogilvie, who won the season-opening Jacob's Creek Open and was runner-up in Knoxville two weeks ago. 'I watch the scoreboard all the time. I like to see who is playing well.'
Murphy had a tame round. He opened with six straight pars before a birdie at the seventh moved him to minus-7. The six-time winner on the Nationwide Tour then parred his final 11 holes.
'A lot of pins were cut in corners of greens today and you've got a two-club wind going out there,' said Murphy. 'It was really hard to think about going for some of those. You're just putting it in the fat part of the green and trying to two-putt.
Wes Short, who survived on the cut line of plus-one, made the big move of the day. He fired a 6-under 65 to move from a tie for 57th into a tie for sixth. He stands at 5-under-par 208 alongside Mark Wurtz, Russ Cochran, Paul Claxton and Scott Gump.