Three years ago at Isleworth, he was making the turn in the final round when he looked over at the scoreboard on the 18th fairway that showed he had a big lead. So it was eerie when he caught himself doing the same thing Sunday during the final round of the Hero World Challenge.
But there was one big difference.
Back then, Spieth was a freshman at Texas and won by eight shots in the Isleworth Collegiate Invitational for his first college title.
This time, he beat an elite field that included tournament host Tiger Woods, six major champions and 16 of the top 30 players in the world.
And he beat them even worse.
Spieth capped off a big finish to his second season as a pro when he closed with a 6-under 66 and set two tournament records to win by 10 shots over Henrik Stenson. Staked to a seven-shot lead in the final round, he opened with three birdies in four holes and turned the final three hours into a peaceful walk along the lakes and palatial homes of Isleworth.
"It was the most fun I ever had playing nine holes of golf," Spieth said.
Spieth had an 11-shot lead after nine holes, ripped a drive over the corner of the bunker and then glanced at the lone leaderboard. And then he made another birdie. He coasted from there and even with a careless double bogey on the back nine, he finished at 26-under 262 to break the tournament record of 266 set by Woods in 2007 and Davis Love III in 2000, both at Sherwood Country Club in California.
The 10-shot victory was the largest margin of the year in golf, and broke the tournament record of seven shots that Woods had in 2007.
"Whether my emotions showed it or not I'm not sure, but inside we were really very pleased with the year and how it came to a close," Spieth said. "This caps off the best golfing year that I've ever had."
Spieth had set a goal of two wins, and that looked out of reach when he began the last leg of a long journey. He finished one shot out of a playoff in Japan, won the Australian Open by six shots and then turned in another dominant performance.
"The kid is playing great," said Keegan Bradley, who had a 70 to tie for third with Patrick Reed (68). "You have to look at his past three events. He almost won them all. He's a great player. I wouldn't look more into it other than he dominated this week."
Woods, in his first tournament in four months while recovering from back injuries, stubbed two more chips on the 13th hole for a triple bogey and closed with a 72. He tied for last place in the 18-man field with Hunter Mahan, 26 shots out of the lead.
Woods noted that Spieth closed with a 63 in Australia and flew some 9,000 miles to get to Isleworth.
"He's playing some pretty special golf right now," Woods said.
Spieth completes his second full year as a pro by moving into the top 10 in the world ranking at No. 9. The Hero World Challenge is not an official PGA Tour event, so the $1 million prize does not count toward the money list.
He had never had such a big lead going into the final round, and it's tempting to try to protect it. Instead, Spieth set tiny goals and came out swinging. One of those goals was to stretch his lead to 10 shots, and he got there with a hybrid on the par-5 seventh to the left edge of the green that trickled onto the putting surface. Bradley two-putted for birdie to get within eight shots, and then Spieth poured in his putt to go up by 10.
Bradley was headed for the eighth tee, when he reversed course and walked over to Spieth to playfully body-slam him.
"I wanted to go over there and tackle him and break his putter," Bradley said. "No, I love Jordan. I'm happy for him. He was pretty much unbeatable this week."
Stenson played with Spieth on Saturday, and knew what to expect.
"He was in pretty much full control of every part of his game," Stenson said.
Stenson closed with a 69 to entrench himself a little deeper at No. 2 in the world behind Rory McIlroy, who did not play this week.
Spieth Enjoys Victory Lap At Isleworth
Carrying the winner's trophy, Jordan Spieth explained to ESPN.com's Michael Collins how he coasted down the stretch as well as taking some good-natured ribbing from playing partner Keegan Bradley.
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ESPN's Bob Harig and Mark Schwarz break down Tiger Woods' week at the Hero World Challenge where his biggest accomplishment might have been staying injury free.