UPDATE 1-Golf-Americans Janzen and Stiles set pace at Deere Run

* Janzen bids for first win since 1998 U.S. Open

* Late birdie earns Stiles share of lead

(Adds Janzen quotes, detail)

CHICAGO, July 9 (Reuters) - Double U.S. Open champion Lee Janzen, hunting his first PGA Tour victory in more than a decade, charged into a share of the lead in Thursday's opening round of the John Deere Classic in Silvis, Illinois.

The 44-year-old American took advantage of rain-softened conditions at the TPC Deere Run, firing a seven-under-par 64 to set the early pace.

Janzen, who has not triumphed since clinching his second U.S. Open title in 1998 at San Francisco's Olympic Club, piled up eight birdies before ending his round with a bogey at the last where he found a greenside bunker with his approach.

He was then caught late in the day by compatriot Darron Stiles who recovered from a bogey on 17 by sinking a seven-foot birdie putt on the 18th green for a matching 64.

"I showed up expecting to hit it good, and then my warm-up session was really good," Janzen told reporters after reeling off five birdies on the back nine.

"My iron game has been the best part of my game over the last 20 years, so that's usually not the part I worry about. I chipped in twice today and if I'm hitting a lot of greens and chip in a couple times when I miss it, that's a great combo."