It wasn't the prettiest or most efficient golf you've ever witnessed. They did not draw the very best out of each other. Not yet, anyway. But there's time.
When Spieth missed his 20-foot putt for birdie on 18 and Thomas made his five-footer for bird, it kept the buddies perfectly aligned on the leaderboard and in position to be paired again Friday.
Why not just call the East Lake starter and make this a standing twosome through the weekend?
Every time these two are paired it is a chance to weigh the difference between golf and those other sports where we expect a certain edge between competitors. Too much hugging between opponents before tip-off or too much giggling at first base when the other guy reaches just feels wrong.
But, in golf, it's a comparative picnic. It's not like Spieth and Thomas were locking arms and skipping down the fairway to the music of Harry Nilsson ("People let me tell you 'bout my best friend."). But there was a running friendly conversation between the two all day. Spieth even spun a story or two when there was time on the tee box -- one that couldn't be overheard on No. 5, but ended with Spieth happily gesturing and issuing a loud, "Huuuuuh!"
In this game, such cordial competition is applauded even.
Another Tour Championship player, Charley Hoffman, was just saying the other day how great it was to see Spieth, cap turned backwards, waiting around to hug it out with Thomas after he won this year's PGA Championship. Just as Thomas, who missed the cut at the British Open, stayed the weekend to congratulate Spieth at the end of his victory there.
"It's pretty cool to see in the game of golf," Hoffman said. "That's really what the game of golf is all about -- camaraderie and playing together and having fun. It's great to see these young kids display that.
"Kids watch us on TV and see (that) even though Jordan loses he goes and shakes Justin's hand and says congratulations. That's the way it should be done."
Inside, Spieth said he would root passionately for his friend to miss a 6-footer if it meant beating him or at least getting into a playoff. Outwardly, the two of them are the unchanging picture of mutual support.