Johnson, Sabbatini and Harman tied for lead after 1st round of John Deere Classic

Replacement caddie Jay Hatch from Davenport, Iowa, wipes his face on the 18th hole during the first round of the 2014 John Deere Classic golf tournament at TPC Deere Run in Silvis, Ill., Thursday, July 10 2014. Hatch replaced Brian Harman's caddie Scott Tway, the younger brother of golfer Bob Tway, after Tway got sick on the course. (AP Photo/Charles Rex Arbogast) (The Associated Press)

Brian Harman watches his approach shot on the 18th fairway during the first round of the 2014 John Deere Classic golf tournament at TPC Deere Run in Silvis, Ill., Thursday, July 10 2014. Harman's caddie Scott Tway, the younger brother of golfer Bob Tway, got sick on the course and was replaced by Davenport, Iowa resident Jay Hatch. (AP Photo/Charles Rex Arbogast) (The Associated Press)

Zach Johnson, Rory Sabbatini and Brian Harman

shot 8-under-par 63s Thursday to share the lead after the first

round of the John Deere Classic.

Johnson and Sabbatini played bogey-free golf, while Harman had nine

birdies and one bogey on the par-71 TPC Deere Run.

They led 2004 British Open champion Todd Hamilton, Australian Steven Bowditch and

William McGirt, the best afternoon finisher, by a stroke.

Johnson, who won the Deere in 2012 and lost it to Jordan Spieth in a

playoff last year, birdied four of his first five holes and was 6

under on his opening nine.

Harman, who bettered his best round of the year by two strokes, was 2

under through six holes when his caddie, Scott Tway, took ill. Jay

Hatch of Davenport, Iowa, a high school basketball coach, volunteered

from the gallery, and carried Harman's bag the last 12 holes, which

Harman played in 6 under.