James Driscoll is one shot off the pace at 11 under through 11 holes of his third round. Second-round leader Arjun Atwal is 1 over on his round through 10 holes and stands at minus-10 for the tournament.
'Well, I'm very happy that we got 10 holes in today,' said DiMarco. 'That saves my legs a lot tomorrow.'
DiMarco found a fairway bunker off the tee at the par-4 first but hit his second shot to 8 feet and converted the birdie try. He added a birdie at the par-4 fourth and ran off back-to-back birdies starting at the par-5 seventh to move into the lead.
'Tomorrow is going to be a long day but the one good thing about it is I don't have to sit around all morning and wait to tee off,' said DiMarco, who is competing for the first time since his playoff loss to Tiger Woods at the Masters. 'I'm just going to try and just keep the pedal on the floor and just try to keep making birdies.'
Tim Petrovic is 6 under on his round through 14 holes and 9 under par for the tournament. Lucas Glover is at minus-9 through 10 holes while J.J. Henry is 9 under through nine.
Defending champion Vijay Singh played 10 holes on Saturday and is part of a group at 8 under par along with Padraig Harrington, Tim Clark, Hidemichi Tanaka and Richard S. Johnson.
Bo Van Pelt is in the clubhouse at 7-under-par 209 after a round of 66. Jay Williamson has also completed 54 holes and is one shot back at 6-under-par 210.