AUGUSTA, Ga. (AP) — In a Masters longing for star power, 20-year-old Jordan Spieth put himself atop the leaderboard and 18 holes away from replacing Tiger Woods as the youngest player with a green jacket.

Spieth kept his poise on a lightning-quick Augusta National on Saturday with a 2-under 70 that gave him a share of the lead with error-prone Bubba Watson going into a final round loaded with possibilities.

Watson started the third round with a three-shot lead. After a chaotic day in which five players had at least a share of the lead at some point, this Masters is as wide open as when it started.

All eyes now turn to Spieth, a 20-year-old Texan who already has shown he can deliver big moments. He talked to himself constantly on the golf course, fell to his knees when he thought his tee shot was in trouble on the par-3 12th and lightly pumped his fist when even the short par putts dropped in the cup.

"Today was moving day," Spieth said. "And tomorrow is about seeing how I can control my game and emotions out on the golf course against guys that have even won here recently. So 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 really looking forward to tomorrow."

Woods was 21 when he won his first Masters in 1997. Spieth would be the youngest major champion since Tom Creavy, who was a few months younger than Spieth when he won the 1931 PGA Championship.

But there's a lot of traffic on the road to a green jacket. Nine players were separated by three shots, and that includes Watson, who won the Masters two years ago and might have the advantage of getting his bad round out of the way Saturday.

After a 7-iron within 6 feet for an eagle on the second hole gave him a five-shot lead, Watson threw it in reverse. He left shots short and long, and his putting became weak and tentative. Despite some struggles on the front nine, Watson still was in position to build a cushion until blowing birdie chances on the rest of the par 5s.

From just over the back of the eighth green, he couldn't get up-and-down. He three-putted the par-5 13th for a par. And after a massive drive on the par-5 15th hole left him only a 9-iron to the green, he went long and failed to convert that birdie chance.

Watson's jaw tightened as opportunities slipped away, and he was lucky to convert two pars at the end for a 74 and a share of the lead at 5-under 211.

"If somebody told me I would have shot 2 over and still be tied for the lead, I would have taken it in a heartbeat," Watson said. "So I got a shot on Sunday."

So do so many others.

Matt Kuchar, who squandered chances to win in each of the last two weeks, hit a pitch from well behind the 15th green that had to be perfect and was, setting up the best of his six birdies in a round of 68. Kuchar, a favorite in these parts from his days at Georgia Tech, was one shot behind along with Masters rookie Jonas Blixt, who fell out of the lead with a bogey on the 17th and shot 71.

A Masters rookie has not won a green jacket since Fuzzy Zoeller in 1979.

Miguel Angel Jimenez, who finished his round about the time the leaders teed off, had a tournament-best 66 and was two shots behind with Rickie Fowler, who had a 67. Lee Westwood (70), Jim Furyk (72) and Thomas Bjorn (73) were at 2-under 214.

"Bubba at this point is keeping me in it," U.S. Open champion Justin Rose said after his 69, leaving him only four shots behind. "There's a lot of players with a chance tomorrow. Anybody under par going into tomorrow has a good shot."

That would not include defending champion Adam Scott, who might have thrown away his hopes with a 40 on the front nine that led to a 76. He was six shots behind.

Spieth fell in love with Augusta National the first time he saw it last October, during a two-day golfing trip that started at Pine Valley. He has leaned on two-time champion and fellow Texas Longhorn Ben Crenshaw in practice rounds, and he met with six-time champion Jack Nicklaus on Wednesday to learn as much as he could.

The kid is a quick study.

He didn't even have a PGA Tour card at this time last year. Since then, he won the John Deere Classic, became the youngest American to play in the Presidents Cup when Fred Couples made him a captain's pick, and had a chance in the final hour to win the FedEx Cup and its $10 million prize.

Phil Mickelson might have seen this coming. He was paired with Spieth the last day of the Deutsche Bank Championship in September, when the kid shot 62. Mickelson called Couples and said, "Dude, you've got to pick this guy."

Now, the young Texan has a good shot to join them in the champions' locker room.