Bill Haas fired a 6-under 66 on Friday to move into a share of first place with Justin Rose at the Arnold Palmer Invitational.

Haas, who is battling neck and shoulder injuries, started the day four strokes behind the first-round leader Rose, but steadily climbed the leaderboard with his bogey-free round to grab a share of the lead at 9-under-par 135.

"We should call it a sore neck, not an injury," said Haas. "When you're playing poorly, it hurts, and when you're playing well, it doesn't hurt."

Rose carded a 2-under 70 during his second round at Bay Hill Club & Lodge.

John Huh (69) sat alone in third place at 8-under, while Ken Duke (68), J.J. Henry (67), and Jimmy Walker (69) shared fourth at minus-6.

Tiger Woods (70) was within a stroke of the lead following his second birdie in three holes at the 13th, but he would get no closer and closed out his day with three straight bogeys to fall into a tie with Vijay Singh (68) and Mark Wilson (68) for seventh place at 5-under.

MORE TO FOLLOW.