Beneath that cap is plenty of gray hair.
Beneath that smile, he knows better.
There's another similarity in the two events.
Kuchar had a 54-hole score of 193 in Mexico, the lowest of his career. He went one lower at the Sony Open at 18-under 192. Kuchar has made only one bogey through 54 holes at Waialae, and he only came seriously close to one bogey until saving par from a bunker on the par-3 17th.
"Good, steady golf," Kuchar said. "It felt easy out there. I didn't find myself in any trouble."
Putnam was two shots behind after a 67.
Keith Mitchell had a 63 to pull within four shots, along with Chez Reavie, who fell back with three straight bogeys early on the back nine. Those were the only players within five shots of the lead, and all of them are chasing Kuchar.
"I anticipate needing another good score tomorrow," Kuchar said. "I know I can't coast."
Kuchar is 2-2 when he has the 54-hole lead going into the final round.
The only other time Kuchar won twice in the same season was in 2013, when he won the Match Play Championship in Arizona in February and the Memorial in early June. That put him at No. 4 in the world, the highest he has been in his career.
Kuchar was sliding his way out of the top 50 toward the end of last year, when he failed to make a Ryder Cup or Presidents Cup team for the first time since 2009. But he had a good session with his swing coach in Dallas, and it paid off two weeks later on the Gulf side of the Mexican coast.
This was more of the same.
Putnam, who won for the first time last year in the Barracuda Championship held opposite a World Golf Championship, did his best to stay in reach. They were tied through seven holes until Putnam made bogey on No. 8 and failed to birdie the par-5 ninth, the easiest hole at Waialae. Putnam missed an 8-foot birdie attempt on No. 18.
"Didn't feel as easy as the first two days," Putnam said. "Still played a good round. Still got a chance."
Bryson DeChambeau had a 63 and led a large pack at 11-under 199, seven shots out of the lead for a slim chance at winning unless the leaders come back to the field. Also tied for fifth were Charles Howell III and 54-year-old Davis Love III, who had one of his better putting rounds.
Kuchar was at his best on a number of putts from the 50-foot range. He didn't make any, but he didn't leave himself any work for par. That added to the stress-free feeling of a round, and the overall control he feels in his game.
"Kuch is playing well, so I feel like I've got to get out there and make some birdies if it's not too windy," Putnam said. "If it's like today, it's going to be scorable. I have to stay aggressive."