Defending champion Rickie Fowler endured a tough opening round as Wyndham Clark grabbed a two-stroke lead at the Phoenix Open on Thursday.

Fowler, who missed the cut at Torrey Pines last week, dropped shots on four of his first nine holes and struggled to a three-over 74, level with Jordan Spieth.

His compatriot Clark found more comfort amid typically rowdy crowd behaviour at TPC Scottsdale, carding the lowest round of his career.

The 26-year-old fired a 10-under 61 that included 10 birdies to move two shots clear of Billy Horschel, who produced an error-free 63.

“I putted really well today,” Clark told Golf Channel. “I made a lot of long putts. I haven’t putted well the last couple of weeks and it was shocking, because it was a strength of mine.

“Throughout my history, I think everyone knows once I get on little run, especially with the putter, I feel like I can make anything from anywhere on the green.

“I love these greens out here. Once I get on that run of seeing putts go in, the hole just looks massive and I see this perfect track going to the hole. All I have to do is make sure I hit it with the right speed.”

Two-time Phoenix Open champion J.B. Holmes hit a bogey, a double bogey and an ace – at the par-three fourth – en route to a seven-under 64.

Jon Rahm, who played collegiate golf at the nearby Arizona State University, made five birdies in a steady four-under 67 to please the local fans.

“It’s fun,” the Spaniard told reporters. “It’s the biggest golf event in the sense of the amount of people who come watch. If you’re a Sun Devil and a hometown favourite you get a lot of people come support you.

“Especially at the 16th, if you hit a good shot and make the putt the cheer is extra loud.”

Justin Thomas (68) and Tony Finau (69) also earned approval for wearing Kobe Bryant jerseys in tribute to the Los Angeles Lakers legend, who died in a helicopter crash on Sunday.