The high school junior shot a 3-under-par 67 yesterday in Irving, Texas, his best round yet. That dropped him to 6-under 204 for the tournament, giving him an outside chance to win his PGA Tour debut. He is tied for seventh, six shots behind leader Jason Day.

“I know the pins are going to be the toughest pins I’ve ever experienced in my life, but I’m confident,’’ Spieth said. “I’m going to start firing because I got nothing to lose, nothing to hold back, might as well try and make a run.’’

On Friday, Spieth became the sixth-youngest player to make a cut. The best finish for someone so young was Italy’s Matteo Manassero, who at the age of 16 tied for 13th at the 2009 British Open.

Spieth opened with a birdie. He then had a rare wild stretch on the third through sixth holes: bogey, birdie, birdie, bogey. He got back to making pars with the occasional birdie mixed in — such as No. 16, where he made a great sand save Friday.

Spieth gave back a stroke with a bogey on the par-3 17th, but rebounded with a par at 18.

LPGA — Top-ranked Jiyai Shin knocked out Michelle Wie in the Sybase Match Play Championship quarterfinals in Gladstone, N.J., winning, 2 and 1, at hilly Hamilton Farm.

Shin will play Sun Young Yoo — a 2-and-1 winner over fourth-seeded Yani Tseng — in the semifinals this morning. In the other quarterfinals, 10th-seeded Angela Stanford beat Catriona Matthew, 5 and 3, and No. 30 Amy Yang edged Haeji Kang, 1 up.

In the morning third-round matches, Shin beat Beatriz Recari, 4 and 3, and Wie overcame shaky ball striking to top Karine Icher, 3 and 2.

European — Chris Wood shot a 4-under 67 for a two-shot lead over Robert Karlsson, who had a course-record 62 in the third round of the BMW Championship in Wentworth, England.

Karlsson finished at 6-under 207, despite a quick turnaround from his home in Monaco after he thought he’d missed the cut. He’s tied for second with Danny Willett (70).

Nationwide — John Riegger shot an 8-under 63 to take a five-shot lead after the third round of the Rex Hospital Open, while high school sophomore Grayson Murray fell off the pace in Raleigh, N.C.

The 16-year-old Murray shot a 1-over 72 and is 2 under overall, 18 shots off the lead.