AUGUSTA, Ga. - For nearly three full days, Jordan Spieth kept any semblance of drama out of the Masters. He was running away with it. Then in the space of 20 wild minutes, he allowed all sorts of tense excitement in, and perhaps enabled a couple of worthy opponents back in the tournament, too.
Through his 16th hole Saturday, it had all been The Jordan Spieth Show. He had turned away the best salvos of both Augusta National -- which weren't much; the course is soft and benign -- and the field, which was playing quite well.
When Phil Mickelson made a rousing 41-foot putt birdie putt on No. 16 and Justin Rose sank a bunker shot on the 16th for birdie, still Spieth led by seven strokes.
Then things got interesting. Spieth double-bogeyed No. 17 and hit his approach on No. 18 into the gallery, to a seemingly impossible position. At that point, Rose and Mickelson had new life in a Masters that suddenly seemed transformed.
But in yet another twist, Spieth tried an ambitious downhill flop shot, put it within 9 feet and made the left-to-right par putt. "It was really big. It was huge. It was one of the bigger putts I've ever hit," he said. "Seeing any putts go in on 18 is nice."
Who knows what he and everyone else will see Sunday. This much is clear: Spieth is at 16 under par, a record low for 54 holes at the Masters. Yet he is only four ahead of Rose, who made his own putt on No. 18 for birdie, and five ahead of Mickelson, who bogeyed No. 17. They both shot rounds of 5-under 67.
This also is clear: It is a different tournament than it was before Spieth went to the 17th tee, fresh off his second consecutive birdie.
"Driver should never have come out of my bag at that point," the 21-year-old leader said as he calmly, clinically described the hook off the tee, the layup, the poor pitch ("When I got up there and saw it, no part of me liked it") and the three-putt six on the par-4 hole.
Maybe that double bogey will prove to be the vulnerable point from which Rose or Mickelson will emerge. Or perhaps the unlikely par save on the 18th, which led to a 70, will rank as the moment when Spieth regained his composure and his hold on the Masters.
The son of two engineers, Spieth calculated the odds of pulling it off as one in five.
"That just took some guts," he said. "Having been in this scenario, having been in contention enough, I felt comfortable enough to play that full flop. If you caught me a year and a half ago, I probably would never have played that shot."
For Sunday, he expects big drama and high volume -- especially for Mickelson, a crowd favorite, who drew huge noise with his birdie on 16. "Crazy. I mean it's crazy to make that putt," Mickelson said.
But not impossible: "I remember in 1991, watching Jack Nicklaus and Tom Watson hit that putt. Both made it. I remember being up in the clubhouse, feeling the ground reverberate from the roar."
Mickelson, a three-time Masters winner, will be in the next-to-last group Sunday with fellow San Diegan Charley Hoffman, who dropped from second to fourth (10 under) after a water ball on No. 15.
Rose, who edged Mickelson for the 2013 U.S. Open title, beat him out again, this time for the coveted spot in the last group Sunday. He did it with a slick downhill putt on 18, capping a run of 5 under through the final six holes. "It's amazing, and it put me in with a great opportunity tomorrow. It's a great lesson, as well, to stay patient," Rose said.
If Spieth shoots 70, as he did Saturday, he will tie Tiger Woods' record of 270, 18 under, which he set in 1997. But nothing about it figures to be easy. "I can't rely on the putter to save me with two major champions right behind," he said. "They are going to bring their game."
And somebody is going to bring home a green jacket.