Dustin Johnson leads on PGA Tour

PACIFIC PALISADES, Calif., Feb. 4 (UPI) -- Dustin Johnson shot a bogey-free, 7-under 64 Thursday to take the lead after the opening round of the Northern Trust Open.

Two-time defending champion Phil Mickelson, who chose not to use a controversial wedge during play this week, struggled with his putter and settled for a 72 over the Riviera Country Club course.

Johnson has won twice on the PGA Tour and challenged for a major title last year before finishing fifth at the PGA Championship. He had a one-shot lead over Andres Romero and Kevin Stadler.

Ricky Barnes and Brandt Snedeker were tied for fourth at 66 while Steve Stricker, the third-ranked player in the world, was among those at 67. David Duval shot his low round of the young season, a 68, and was tied with Ernie Els and 18-year-old Japanese star Ryo Ishikawa.

Mickelson was 3-under through 11 holes, but played the final seven in 4-over.

He did not carry his Ping Eye 2 wedge during the opening round, having announced earlier in the week he would try to avoid controversy by abandoning the club. Although the 20-year-old club has been cleared for play by the PGA Tour, some players feel using it breaks the spirit of the rules because newer, similar clubs have been banned.

Scott McCarron accused Mickelson of cheating last week when Mickelson used the club. Mickelson said he had been slandered and McCarron eventually apologized.

McCarron, who has not made a cut in three tournaments this season, shot a 74 Friday.