The bizarre incident happened after the tees at the ninth and 17th holes at Albany Golf Club were switched for the final round of the event hosted by Tiger Woods, with Stenson and Spieth being caught out by the change in the first group of the day.
They were walking up the ninth fairway when a rules official caught up with them in a buggy to point out the error, which left them having to walk back and hit off again from the correct tee.
“We kept our heads down after finishing out on hole No 8 and walked to the No 9 tee box that we did on Wednesday, Thursday, Friday, Saturday and put the ball down and hit some beautiful tee shots,” said Stenson, the 2016 Open champion, afterwards.
“Then, when we went down to the balls, the rules official said, ‘did you hit off the right tee box?’ And we're like, ‘well, yeah’, and then we looked back and we saw that there was another one forward and left.
“So obviously they switched things around and put 17 on the ninth tee box today and nine was in a different place and we didn't pay attention being first out and just motoring along. It was just go back and reload.”
Standing beside the Swede as they faced up to the mistake together, Spieth said: “Personally, I've never experienced that before. They said in the scoring there was a sheet saying that there was a new yardage on No 17, but there was nothing about No 9.”
Asked what his reaction had been, the two-time major winner added jokingly: “I actually didn't think we were going to get penalised because it's a charity event, but then I realised there's world ranking involved and all that.
“I think the frustrating part for us now is that every other group they're making sure to tell them, but, for us, they didn't.”
The duo filled the final two spots in the 20-player event as they were the only ones to finish over par for the week.
“My question was if we could just finish 19th and 20th and leave after nine, but that wasn't an option,” said renowned joker Stenson, who was certainly taking that tone when he was asked if it had been an easy mistake to make.
“I'm a little offended by that because then you think I'm really stupid,” he replied to that before turning hilarious after Spieth revealed that he’d been set to tee off first before it was pointed out that it was Stenson’s honour then had to be told to “scoot back” after he’d teed up a fraction in front of the markers.
“Now you just spoiled the whole thing,” said Stenson, laughing. “Like look at these guys, they don't know who's going to hit. Once they figured out who's hitting, one guy's trying to tee up in front and then they both hit from the wrong tee box. It's like I guess we got what we deserved.”