Senden birdied three of his final six holes in the third round, rolling in a 7-foot birdie putt at the 18th to complete a bogey-free day. He stands at 16-under-par 197 and holds a 54-hole lead for the first time on the PGA TOUR.
Senden, 35, owns three international titles -- the 1996 Indonesian PGA Championship and two European Challenge Tour wins -- but his best-ever PGA TOUR finish was a tie for fifth at this year's Bob Hope Chrysler Classic.
This is a tournament where first-time winners have won frequently -- Sean O'Hair did it last year and David Toms broke through in 1997 -- so Senden's position isn't exactly a unique one.
'I'm going to go out there tomorrow and really feel great about myself,' Senden said. 'I probably will be nervous. I haven't held the lead after three rounds, so I'm really looking forward to the challenge.'
Overall, there are nine players within five shots of Senden heading into the final round at Deere Run.
'Someone is going to need to shoot low around here because it's really a low- scoring course if you're playing well,' Senden said. 'I've just got to go out there and be competitive and do my stuff.'
One day after Michelle Wie withdrew because of heat exhaustion, the focus Saturday became a scramble for the lead.
Senden came out on top with seven total birdies, including two straight at Nos. 1 and 2 to begin his round. He added a third birdie at the eighth before making the turn.
Another birdie at the 10th moved Senden to 13 under, and that's when he made his real move.
At the par-4 13th, Senden rolled in a 40-foot birdie put that moved him two ahead before Sheehan responded with his own birdie at 13. Two holes later, Senden drained a 10-footer for another birdie and a two-shot lead that stood.
Senden found trouble off the tee at the par-5 17th, where he knocked his drive into the rough but got a fortunate lie. After landing his second shot within 50 yards of the green, he scrambled for par to maintain his two-shot advantage.
At the par-4 finishing hole, Senden made a seven-foot birdie putt to extend his lead to three shots.
On Sunday, such a putt will come with a little more pressure. Senden might not want to think about the last two 54-hole leaders here, who both held three-shot leads and didn't win.
'I can't control a score,' Senden said, 'but I can control how I react to any good breaks, any bad breaks. That's how I'm going to handle it tomorrow.'
Senden, who is currently ranked 63rd on the money list, said he would accept an invitation to next week's British Open if a win here earned him a berth.
'Winning would mean a lot because there's a lot of other Australian players out here that have won, and to join that group would be great,' Senden said. 'I'm really looking forward to getting to that next level and satisfying myself that way.'
Sharing fourth place with Ogilvie at 12 under were Alex Cejka (64), Steve Jones (66), J.P. Hayes (66) and Daniel Chopra (68). Daisuke Maruyama and B.J. Staten both shot 66 and are tied for ninth place, one shot further back.