DiMarco, who last won in late January, heads the field on a 36-hole Disney record 17-under-par after a bogey-free round that included an eagle at the par-five 14th.

"If I keep doing what I'm doing, I'm going to be tough to beat," DiMarco said.

"I've been putting absolutely phenomenal.

"My putts are going dead-center, and I'm making all the little ones that can be tricky out here.

"Anybody out here who gets hot with their putter, that's going to happen. And I'm kind of riding it."

The Japanese is one shot adrift in third after a 67 with fellow early co-leader Bob Burns another shot back after a 68.

World number one Tiger Woods is nine under, after a second-round 69.

Woods is level with England's Luke Donald who compiled rounds of 67 and 68.

The low scoring meant the cut came at six under which was too good for David Duval.

The Open champion posted a second-round 70 to finish on five under.

"I'm going to miss the cut," said a stunned Duval. "That never even crossed my mind."

Woods is eight shots off the pace, his largest 36-hole deficit since he was 10 strokes behind at the Memorial in late May.

He said: "I've never seen anything like that before, this many guys going that low."

First-round co-leader Jeff Sluman escaped the cut on 11 under, while Germany's Ryder Cup hero Bernhard Langer was also set for the weekend on 10 under after a two-under-par 70.