IRVING, Texas (AP) — Jordan Spieth finally felt like a kid teeing it up against the big boys on the PGA Tour.
The golf part wasn't what troubled the 16-year-old high school junior.
His dilemma was whether to call Tom Pernice Jr., his 50-year-old playing partner, "Mr. Pernice" or "Tom."
While Spieth never actually figured that out - alternating between the two, then avoiding it - he continued to defy the expectations of everyone but himself, shooting a 3-under 67 Saturday to move solidly into contention going into the final round of the Byron Nelson Championship.
Spieth's best round yet left him tied for seventh, six shots behind leader Jason Day, and injects all kinds of intrigue into an event that was thought to be missing an attention-grabbing headliner.
"I know the pins are going to be the toughest pins I've ever experienced in my life, but I'm confident," said Spieth, who just last week was competing in a high school state tournament (which he won). "I'm going to start firing because I got nothing to lose, nothing to hold back."
Day shot a 3-under 67 Saturday to pull into the lead by himself. He was part of a seven-way tie after the first round, then was a stroke behind after the second round.
A win would be the first of his promising career. Considering he's 22, that would normally be a big deal; this week, it almost seems old.
Day actually is a fitting foil to Spieth-mania. Three years ago, he won a Nationwide Tour title, making him the youngest winner of a PGA Tour-sanctioned event. His best finish in a PGA event is second in 65 events.
"Certainly it's playing on my mind a little bit, my first big-time chance," said Day, an Australian who lives in Fort Worth.
Second round co-leader Blake Adams shot even-par 70 and is two strokes back. The other co-leader coming in, Cameron Beckman, shot 1-under 69 and is tied for 13th.
Spieth (pronounced SPEE-th) is certain to have a huge following Sunday.
As if his play, his poise and the fact he's from Dallas haven't won over enough fans, tournament organizers came up with a promotion in his honor: Anyone 16 and under will be let in free for the final round.
The juiced-up environment can only help the kid. He's been feeding off it all week.
"After you hit each shot, you're walking to your next shot or in between holes and everyone is cheering you on," Spieth said. "It gives me goose bumps. I've just got to get out there and settle myself down and try and get them excited and give them something to cheer about."
He did Saturday, holing out a bunker shot for a birdie on No. 1. He called the ensuing roar the loudest he's ever heard.
After a par, he went through a bit of a wild stretch: bogey, birdie, birdie, bogey. Then he got back to making pars with the occasional birdie mixed in, such as sinking a 38-footer on No. 12.
"I'm getting a little jumpy in between shots, I'm walking really fast, and I realize that; I just can't help it," said Spieth, who has been coming to this tournament since he was 5. "But when I'm getting to the ball I'm remaining calm. ... I've only made a couple (bad decision) this whole week, which is normal for a 16-year-old like me. But, you know, I think controlling my emotions has been my strength."
He proved that again at the end of his round.
After making a bogey on the par-3 17th, he came away muttering, "So unnecessary!" Then he put his tee shot on 18 into the rough on the first fairway.
His approach had to clear a bunch of trees to a hole surrounded by sand, with water nearby, too. Spieth hit it so perfectly that he gave his iron a twist and stifled a smile as he walked to the green.
He wound up in a bunker, but was able to get the ball within 8 feet. He made the par-saving putt, gave a few fist pumps and walked off thinking about what could happen Sunday.
"I think I can make a run," he said. "Starting the entire week, y'all gave me odds like 1,000 to 1 or a million to 1, something like that. No one expected me to make the cut, and I guess I have an outside chance. If I get the right conditions out there, the wind starts to pick up and I start just dropping bombs from all over the place, it could happen."
When the round ended, Pernice shook Spieth's hand and offered some advice. Or maybe he was getting Spieth's phone number to pass along to his own daughters, who are 15 and 16.
"I said, 'Great playing, proud of how you hung in there, have fun and good luck tomorrow,'" Pernice said. "He's a wonderful young guy and he's got a lot of exuberance, a lot of excitement in him, which is great. He thrived off the crowd, and the crowd continued to edge him on. ... It's great for the tournament. He's going to bring thousands and thousands of people out here see the event. You don't need Tiger and Phil always to have a great event."
The first time Spieth said "Mr. Pernice," his playing partner said to call him Tom. Only, Spieth didn't hear it.
"So I went back and forth," Spieth said. "I don't call my friends' parents by their first name ... and I ended up just skipping it altogether. I was just like, 'Good shot.' I wouldn't say anything after that, or be like, 'Nice putt.'"
Spieth's manners will be put to the test again Sunday. His playing partner: 50-year-old Corey Pavin.
Pavin also is the U.S. Ryder Cup captain, but let's not get too carried away.
Spieth already has become the sixth-youngest player to make a cut. The best finish for someone so young was Italy's Matteo Manassero, tying for 13th at the 2009 British Open last year, when he was 16.
Regardless of how things turn out, Spieth has plenty of other big events to look forward to, like a sponsor's exemption into the Memphis PGA Tour stop in June, and defending his title at the U.S. Junior Amateur Championship in July.
But, first, he's got homework to catch up on and a junior amateur event next weekend.
"It will be different," he said, "but, you know, it will almost feel more natural."
Surely he'll call those playing partners by their first names. If anything, they might call him Mr. Spieth.