Saturday was a round for the sages at the Masters. The greens were faster and more adventure-filled than Hugh Hefner’s pool deck. The conditions required the patience of a buzzard. If you didn’t know every nook and mood of Augusta National in this state, then you had no shot.

So, of course, it was a 20-year-old with all the real-world experience of a Labrador puppy who ascended to the leaderboard’s summit.

Playing for the first time here, Jordan Spieth will tee off in the final twosome Sunday in the company of co-leader and 2012 Masters champ Bubba Watson, both at 5 under. That’s Mr. Watson to someone of Spieth’s tender years.

Yes, he said he’ll actually address him with that honorific on the first tee. “Yeah, Mr. Watson, for sure,” Spieth said, smiling, “just because it’ll mess with him.”

“That’s fine when I’m hitting it past him,” Watson countered.

While Spieth was shooting an impudent 70 on Saturday, his third sub-par score in as many lifetime Masters rounds, Mr. Watson was giving back the substantial lead he built over the first two rounds. His flat stick went flat. He needed 33 putts Saturday, which ranked him 38th in the 51-man post-cut field.

He suffered his first two three-putt greens of the spring. His 74 — which required a nifty up and down from the patrons on No. 18 — opened the door to all sorts of possibilities Sunday.

Watson had a three-shot lead at the start of day that went to five after he eagled the par-5 second. By the time he was leaving the eighth hole, any lead was gone, as he was tied with a Bjorn (Thomas) and a Blixt (Jonas). Game on.

Five under represents the highest third-round leading score here since 2007. Such suppressed scoring kept all kinds of players in the mix. There are 13 of them within five shots of his and Spieth’s lead.

Hope there’s enough hours of daylight left Sunday to sort out this mess.

“Anyone within five, even six shots of the lead going into the final round of the Masters is given a good chance, especially with the way the golf course is playing out here,” Lee Westwood (2 under) said. “You can make even a good shot and drop shots out there. You are kind of on the knife edges of the greens. It’s getting faster and firmer.”

Among the notables in reach is former Georgia Tech star Matt Kuchar — one back at 4 under — who has finishes of tied for third and tied for eighth in his past two Masters tries. “This is a position all of us hope to be in when we show up on Monday or Tuesday,” Kuchar said. “It’s one of those special places, and it’s awfully exciting to be in this situation.”

Old guys made their mark on the day. A 50-year-old, Miguel Angel Jimenez had Saturday’s low round, a 66. And Fred Couples, 54, was still under par, 1 under, and stubbornly resisting a life of high-wasted pants and 5 o’clock dinners.

But it was Spieth, whose youth makes even the quest of 25-year-old Rickie Fowler (3 under) to win his first major appear dated, who was the topic of Saturday.

That he could compose himself so totally on greens that veterans were calling the quickest they had witnessed in years was revealing. Spieth took his 12 pars Saturday and picked his spots to go for a little more. He had one of the more mature rounds of the day, a 70 without any great trauma.

“I have a lot of respect for this golf course,” Spieth said. “It seems by the scores to be playing as difficult as it has in quite a while. And with that, you have to just accept par and accept the fact that you’re going to have some wicked fast putts. And it’s not like hitting the smart shot gets you an easy par. You still have to work for it, and that’s why I’ll lose some more hair as we go on.”

“He’s special,” Couples said. “When you’re that kind of a player you can play well anywhere. I mean he’s such a great putter. He hits the ball long and high. But for a 20-year-old, you know, he’s pretty savvy. Not much bothers him.”

When the kid and his caddie ran into Watson on the practice tee before Saturday’s round, “They said, ‘We’ll see you in the last group on Sunday,’” Watson recalled.

“And I was like, ‘You’d better play good.’ But obviously I should have played a little bit better,” Watson said.

When Spieth began talking afterward about the challenges he faces Sunday, he was candid without ever sounding callow.

You try to find the youth and inexperience — anything that will put him at a serious disadvantage Sunday — in his words. It’s almost impossible.

“I don’t think I’ve ever had a round where I’ve been nervous on every single swing, shot, and putt,” he said. “I’m sure that will happen tomorrow, but hopefully I can channel it positively and stay grounded, stay cool, and see what happens.

“(Sunday) is about seeing how I can control my game and emotions out on the golf course against guys that have even won here recently. They have been in the position I haven’t. Doesn’t necessarily mean, I don’t think, that they have an advantage in any way.

“I think that I’m very confident in the way things are going, and I’m really looking forward to it.”