His game traveled with him.
One week and half-a-world away from his six-shot victory in the Australian Open, Spieth was practically flawless Saturday at Isleworth. He opened with three straight birdies and capped his day with a 50-foot birdie putt for a 9-under 63 and a seven-shot lead over Keegan Bradley and Henrik Stenson.
''Felt strong coming off last week,'' Spieth said. ''Job is not done this week, but I'm a believer in my own momentum. I'm going to go out tomorrow with a very similar strategy to today. If the putts go and the breaks go my way, hopefully shoot a round like today. If not, I'm still going to have to shoot under par to win this golf tournament.''
Spieth was at 20-under 196.
He said he has never been 20 under on any course through 54 holes, and he has never finished a tournament that many under par. That gave him a target for Sunday, when he goes after his second straight victory.
Tournament host Tiger Woods was 20 shots behind and in dire need of his antibiotics taking effect. Woods lost his voice overnight and had nausea on the practice range and the golf course. He felt slightly better at the end of his round when he made three straight birdies for a 69.
He remained in last place.
Bradley made four straight birdies around the turn on his way to a 65. He will play in the final group with Spieth.
''I've got to shoot a low one and get some help from Jordan,'' said Bradley, who has not won in more than two years. ''He's such a good player. I don't expect that. I'm going to have to shoot a really low one.''
Stenson, who played in the final group with Spieth on Saturday, recovered from a sluggish start with four birdies over his last eight holes for a 68.
''I don't think anybody is going to catch him tomorrow unless he's having a really bad day,'' Stenson said. ''Seems to be a one-horse race going into Sunday. He's a very solid player and playing solid golf at a very young age.''
Stenson recalls Spieth making a spirited charge at the Swede in the Tour Championship last year. He also is aware that Spieth finished one shot out of a playoff in Japan and won in Sydney against a field that included Rory McIlroy and Adam Scott.
''We're going to see a lot of him in the years to come,'' Stenson said.
Spieth elected to return Saturday morning to complete the rain-delayed second round instead of finishing in darkness. He had clear vision in the morning – not only of his chip to 5 feet to save par, but of Steve Stricker's 50-foot birdie attempt across the green.
Spieth had about the same putt later in the day, only going in the opposite direction of Stricker's putt. That at least gave him an idea of the speed, though he had imagined a 3-foot circle around the hole that he would have accepted to walk off with par.
This turned out even better. The putt dropped for an unlikely birdie, and Spieth raised his putter as it dropped. He was all smiles walking off the green.
''I put my putter up, which usually means it will find a way to lip out,'' Spieth said.
No chance on this day.
He opened with an 18-foot birdie putt on No. 1, got a good bounce with his 7-iron on the par-3 second to about 8 feet, and then made birdie on the par-3 third. After that, his iron play and his short game – always exquisite – were so good that he didn't need to make any big putts.
Wrapping up his second full season as a pro, Spieth gets a new experience on Sunday - playing with a big lead.
''I think I've got to have a number tomorrow to go out and really chase,'' he said. ''I haven't finished in the 20s (under par) before ever in my career, and I think most of the guys that are in this event have somewhere. So that would be a good goal, to go out there and shoot under par. Hopefully, it's good enough.''
Bradley will be chasing with a short putter, as he has done this week ahead of the Jan. 1, 2016, ban on the anchored stroke used for his belly putter. Bradley in the 2011 PGA Championship was the first player to win a major using a belly putter.
''I've had five years and hours and hours of practice that are now taken away from me,'' he said. ''But it's fun to come out here and prove to everybody and myself that it's not a big deal. This is probably the best three days of putting I've had in a couple of years.''