TUCSON, JAN. 11 -- Craig Stadler is rather fond of the TPC at Starpass. But then, he should be. He was a consultant on the design and construction of the home course for the Tucson Open.

And he liked it even more today after touring the hilly layout in 8-under-par 64, good for a one-stroke lead at the halfway point.

"The course," he pronounced in mock seriousness, "is finally playing the way we wanted it to."

Stadler, who scored his last American victory in 1984, played the par-5 holes in 5 under and one-putted 10 times.

"Surprise, surprise," said Stadler, who hadn't played since Thanksgiving and was using a new set of irons, a new wedge and a driver he'd used only twice before.

"I'd come to Tucson hoping to get in some good practice for the Hawaiian Open," he said. "Obviously that has changed."

Stadler was at 11-under 133 after one round on each of the two courses used for the first two rounds of this event.

Eleven others -- including amateur Phil Mickelson -- are within three strokes of Stadler's lead going into the final two rounds, both of which will be played at Starpass.

Brian Tennyson, Scott Hoch, Corey Pavin and first round co-leader Bob Tway are a single shot behind at 134. Tennyson shot 65 and Pavin had a 67 at Tucson National and Hoch had a 66 at Starpass.

"A lot of people have a chance in the last two days," Tway said after a 70 at Tucson National. "It'll be a kind of a shootout. You just have to go out and try to shoot as low as you can."

Gary Hallberg, who bogeyed his final hole for a 69 at Tucson National, and John Cook are at 135, two back. Cook had a 69 at Starpass, despite what he called "a couple of bonehead, first-tournament-of-the-year mistakes."

Mickelson, a left-handed Arizona State junior who holds the U.S. Amateur and NCAA titles, had a 71 at Starpass and is tied at 136 with Peter Persons, Canadian Ray Stewart, Hal Sutton and Rocco Mediate.