The 17-year-old amateur birdied the first two holes Saturday. He was 5 under and within three strokes of the lead before hitting a couple of tee shots into bunkers. He finished with a 2-over 72 and was 1 under for the tournament, only four strokes behind leader Ryan Palmer (73).
Spieth's round ended about 4 p.m. time, the same time the other 245 boys in the senior class of Dallas Jesuit Prep were beginning their graduation ceremony on the SMU campus about 20 miles away.
Because of expected traffic, Spieth's mother said they wouldn't try to get to the ceremony, which was also near where Cowboys quarterback Tony Romo was getting married.
With a large gallery following Spieth and playing partner Jerry Kelly, the teenager opened with a 10-foot birdie putt.
Then on the 190-yard No. 2 hole, with heavy winds bending the flagstick tucked on the front left of the green, Spieth hit his tee shot inside 3 feet for another birdie.
"I was like all right, who knows what can happen, who says you can't shoot 5, 6 under today. And then reality kind of kicked in," Spieth said. "I caught a couple of bad breaks. But also within those bad breaks, I made a couple of amateur decisions, which definitely hurt."
Spieth's first hiccup came when his tee shot at the par-4 fourth hole landing on the facing of a fairway bunker. After blasting out only 50 yards — with one foot in the bunker and the other out — his third shot hit and then rolled through the green. When the ball rolled off the back of the green, Spieth gritted his teeth while dropping into a half squat and gripping his club hard with both hands.
After he chipped to 8 feet off, he two-putted for double bogey.
Before his first putt at No. 4, Spieth stood in front of a leaderboard which had his name directly below Palmer and Sergio Garcia, then the co-leaders who had not yet teed off.
Spieth (pronounced SPEE-th) had another bogey at No. 9 when he hit another fairway bunker, then found a greenside bunker before blasting to 5 feet. After an 11-foot birdie on No. 10, his first tee shot at No. 11 went out of bounds and he had a double bogey 6.
"On four or five holes today I made four or five swings where I wasn't ready to hit me. And it cost me five shots," he said. "But, you know, I'm happy today the ball is rolling on the greens and my putter is keeping me in this and helping me. Maybe one of these rounds I'll find a way to not make any bogeys."
With winds were sustained at 25 mph with gusts near 40, it was a tough day for scoring. There were only eight under-par rounds among 74 players, the best a 3-under 67.
After a birdie at the par-4 14th, Spieth had consecutive bogeys before a 10-foot birdie putt at the par-3 17. He then had a 7-foot par-saving putt after missing the green with his approach at No. 18, where he was greeted with a roaring ovation from the fans.
"I'm actually in a good mood because I finished well on 17 and 18," he said.
It is the second year in a row the Spieth made the cut at the Nelson. He finished tied for 16th last year and was within three strokes of the lead after 10 holes in the final round. He received a sponsor's exemption to play in the tournament again this week.
His caddie this week is another local amateur, and his future teammate when they get to the University of Texas next fall. He is carrying Spieth's "Jesuit Rangers" bag from his high school team.
Spieth, a past U.S. Junior Amateur champion, plans to take part in a U.S. Open qualifying tournament June 6 in Dallas.
When Spieth made it to play the weekend rounds as a 16-year-old at the Nelson last year, he was the sixth-youngest person to make the cut in a PGA Tour event.
After Spieth's second round Friday, Dallas Mavericks owner Mark Cuban tweeted: "Shout out to Huge Mavs Fan JORDAN SPEITH.. Congrats and Keep it rolling !!!"
Spieth was sitting in a suite with tournament officials and other golfers Wednesday night at the American Airlines Center when the Mavericks won Game 5 of their Western Conference finals series against Oklahoma City to earn a spot in the NBA Finals.