Coming off a seven-week break, Kuchar shot a seven-under 64 in perfect afternoon conditions at TPC Scottsdale for a one-stroke lead over defending champion Hideki Matsuyama and Brendan Steele.
“I was able to be home, able to be dad,” Kuchar said about the layoff. “The boys got to play basketball. Got to go to the games and it was great fun for me. My boys are 9 and 7. Getting into golf. In the afternoon, we'd sneak out and play a few holes.”
The crowd was estimated at 103,420 on the stadium layout.
“Someone told me it was five million,” Kuchar joked. “So many people out here. It's a good buzz. It's a good vibe.”
He made a 25-foot eagle putt on No. 13.
“Chased a three-wood up on the corner of the green, and it was a pretty straightforward 25-footer,” Kuchar said. “That was a lucky place to be on that hole. Some of these pins were hard to get at. That was one that was hard to get at.”
Matsuyama had a bogey-free round in the morning. Last year, he beat Rickie Fowler in a playoff.
Steele holed out from 194 yards for eagle on the par-four 14th.
Fowler, 2015 winner Brooks Koepka, two-time champion J.B. Holmes, Steve Stricker, Martin Laird, Webb Simpson, Graham DeLaet and Alex Cejka were at 67. Stricker is making his first start of the year. He will be 50 on Feb. 23.
Sung Kang also was at four under on the final hole when play was suspended because of darkness.
Fowler made a 16-foot par save on the par-four 11th — his second hole of day — after driving into the water.
He was three strokes better than playing partners Jordan Spieth and John Rahm, the former Arizona State player who won Sunday at Torrey Pines for his first PGA Tour victory.
Spieth also saved par on 11 after hitting into the water, rolling in a downhill 50-footer. He struggled to find the fairways, and had a three-putt bogey on the par-four 17th — missing from 1 1/2 feet.
Phil Mickelson opened with a 68 in his third straight start in his return from two sports hernia surgeries to top playing partners Justin Thomas and Adam Hadwin, the latest players to shoot 59. Thomas birdied 16 and 17 in a 69, and Hadwin shot 71.
Woods struggles in Dubai
Sergio Garcia took advantage of better playing conditions in the morning and carded a seven-under 65 for a one-shot lead to open the Dubai Desert Classic.
Playing ahead of Tiger Woods, who could not make any headway and posted a five-over 77, Garcia made six birdies and an eagle before finally dropping a shot on the eighth hole, his 17th.
Chile's Felipe Aguilar and South Africa's George Coetzee were tied on 66, and the resurgent Ian Poulter led a group of four players with 67. Henrik Stenson, the highest-ranked player in the field at No. 4, posted a bogey-free 68. Danny Willett started his title defense with a 71.
Six players didn't finish because of poor light. None were threating the leaders.
Woods missed fairways and greens, and he needed 33 putts in his second comeback event. “I left probably about 16 putts short. I just couldn't get the speed of these things,” he said.