Matsuyama was simply happy to have a chance.
What struck him about the Plantation Course when he arrived was how big and beautiful it was. He opened with a 70, only to rally with rounds of 66-66 the last two days to reach 17-under 202 and tie Walker, who had a 67 on Sunday.
"If I can play tomorrow like I did yesterday and today, I think I'll have a chance," Matsuyama said. "I think obviously that's going to be difficult to do. I hope to be relaxed and be able to play my golf tomorrow."
Walker has been even more steady and has just one bogey on his card all week. He opened with five birdies in 10 holes on Sunday to build a two-shot lead, then spent most of the back nine making pars until a two-putt birdie on the par-5 18th from just off the green for a 67.
Walker will be going for his fourth win in his last 31 starts on the PGA Tour. He has gone through this before.
"I'm sure I'm going to feel more comfortable, just being out here longer, more mature, more experienced, that type thing," he said. "I'll tell you I was nervous driving to the first tee on Friday for the first round and didn't eat all my breakfast this morning because I was pumped about the day. So I'll be excited and ready to go."
Matsuyama qualified for his winners-only start to the year by winning the Memorial. He was hopeful that would lead to more wins, though his only victory since then was a playoff win in Japan at the end of last year at the Dunlop Phoenix.
"After winning the Memorial, I gained some confidence, and I thought that would translate into playing better after that," he said. "I really didn't get another chance to win, and so now I'm here, I have a chance, and so I want to be able to use that experience I had at the Memorial and hopefully have a good day tomorrow."
Otherwise, Matsuyama remains somewhat of a mystery. He doesn't share much of himself in any language.
Asked why he plays Kapalua so well " only three players in 16 years have won in their debut " he said, "I like the view and so I like the course."
And how does he spend the perfect day away from golf?
"There's not that many days that I'm not playing golf, and so I don't know," he said.
This week has been all about golf. He can see the occasional splash of a humpback whale in the ocean below the Plantation Course. There is snorkeling available in Kapalua Bay, perhaps a paddle board or even some surfing.
"I can't swim, so I can't do that," he said with a smile.
The golf is working out just fine so far. And that's been the case for Walker, who has a chance on Monday to join Els, Vijay Singh, Zach Johnson and Jim Furyk as the only players to win on the courses that make up the Hawaii swing. Els did it in the same year.
Walker's best break led to a par. He tried to drive the 14th green and it sent well off to the right into native grass, a spot where players don't often find it. Two marshals were on the case " and it helped that the grass has been cut to a foot high " and Walker was able to chop it out short of the green, and then hit a beautiful chip to a foot.
"The worse swing I made all day, probably the worst swing I made all week," he said.
There hasn't been many. Now he has one more day against a rising Japanese star who is trying to make his own highlight film this week.