Yang leads pack in Phoenix
South Korea's YE Yang was the early leader at the PGA Tour Waste Management Phoenix Open after carding a seven-under-par opening round of 64.
The 2009 USPGA champion was only one under at the turn, but had six birdies in a flawless back nine to surge to the top of the pile.
He was one shot clear of American duo Pat Perez, who recovered from being one over through seven to post his 65, and Kevin Stadler.
Hunter Mahan and 2011 USPGA champion Keegan Bradley were among a cluster of players a further stroke back on five under after their first rounds.
Scotland's Martin Laird was the best-placed European after signing for a 67, an eagle at the par-five 13th hole the highlight of his day's work.
European Ryder Cup trio Nicolas Colsaerts, Martin Kaymer and Ian Poulter all registered solid opening rounds of 69.
England's Lee Westwood was one under through eight holes, with Ireland's Padraig Harrington level par through 10.
Defending champion Phil Mickelson, whose participation had been in doubt due to a back injury, had an eventful level-par round of 71 which included five birdies, three bogeys and a double-bogey five at the par-three 12th hole.