It's not as if Jordan Spieth didn't warn us.
Everything looked to be smooth sailing for the in-form local hero when he drained a bomb on the final hole in round one to tie the lead thanks to a brilliant 9-under 63.
That flash of the blade caused his odds to come crashing down to 11/4. Spieth was the clear favourite.
But when interviewed later, the Texan revealed he'd tested positive for Covid-19 after finishing third at the Masters and had arrived at TPC Craig Ranch this week with energy levels a little low.
When he returned to the course on Friday, Spieth didn't quite have it. He had to settle for a two-under 70 and reflected: "I was a little tight starting out today for sure. It transferred into my swing. I mean, I'm young enough there shouldn't be any excuses. I'll be fine. Just get some treatment and some compression pants and be ready to go tomorrow."
While building on a 63 with a 70 is generally a good way to consolidate, the low scoring at TPC Craig Ranch this week meant Spieth ended round two six shots off the pace.
The new leader is Sam Burns, who roared to 17-under via a majestic 10-under 62 - his lowest round on the PGA TOUR. That put him two clear of Sweden's Alex Noren.
It's a familiar place to be for the 24-year-old and this is now Burns' fifth 36-hole lead/co-lead of the season.
On the most recent occasion - at the Valspar Championship two weeks ago - he converted for the first time to claim his maiden PGA TOUR victory.
Burns, also a Texas resident, hasn't played since that Florida success. So another triumph here and he'd become the first player since Camilo Villegas in 2008 to win his first two PGA TOUR titles in consecutive starts.
He's now the hot favourite to do so given the relative lack of star power on the leaderboard.
Burns heads the field at -17, with Noren -15, K.H. Lee -14, Doc Redman -13 and J.J. Spaun -12.
The American's sparkling form has also caused his odds for next week's PGA Championship to come crashing down. Burns is 40/1 at Paddy Power to win the year's second Major.
Paddy Power odds after 36 holes: 13/8 Sam Burns, 11/2 Alex Noren, 10/1 Jordan Spieth, 12/1 K.H. Lee, 14/1 Doc Redman, 25/1 Charl Schwartzel, Matt Kuchar, 28/1 Carlos Ortiz, 40/1 Patton Kizzire, 50/1 Bryson DeChambeau, Marc Leishman, Brandt Snedeker, Seamus Power, J.J. Spaun.
Here are the best stats, quotes and social from TPC Craig Ranch after 36 holes.
Stats and facts
Sam Burns leads the field in Strokes Gained: Tee to Green (+8.946).
He ranks 10th in Strokes Gained: Putting and has 100% Scrambling figures.
The leader has made 15 birdies and an eagle to hit 17-under; he's yet to drop a shot.
Spieth's putter cooled down on day two. Putting stats through two rounds: R1 (26 putts; 121' 7" of putts made), R2 (28 putts; 61'3").
After leading the United States to victory in last week's Walker Cup, Cole Hammer (-5), Pierceson Coody (E) and Tyler Strafaci (+6) all missed the cut.
The scoring average in R1 was just 68.750. It increased to 70.368 in windier conditions in R2.
Sam Burns after his 62
"Everything out there felt great. Just feel like we got into a good rhythm throughout the round. Made a run right there on the back nine, and so it was nice to be able to finish it off with two birdies at the end. Good way to end the day. Just trying to get a good game plan out here for tomorrow and let's see what happens.
"The biggest thing for me is just seeing the hard work that we put in it, start seeing results from that. A lot of times you don't know how long the results are going to take. Golf is a fickle game. It's cool to see some feedback from the progress we've made back home and seeing it in tournament play as well."
Alex Noren after his second-round 64
"Most of the stuff was working pretty good. You know, it was just a nice day. You know, I thought it was going to be a -- it was a lot windier than yesterday. We played early yesterday morning. It was nice, no wind, and today I putted well. Got it going, and so did the other guys in my group, and it helps.
"I mean, the fairways are wider which I like, so I've never hit so many fairways I think. I'm not always the straightest so this helps. Playing from the fairway a lot helps. I played the par-5s nice this week I think, so -- and the putting has been there, so it's been a good week so far, yeah."
Jordan Spieth after following his 63 with a 70
"Knowing that the wind was going to pick up on the back nine I thought shooting 5-under was kind of a good goal today if I played well. Just got off to a poor start. I mean, being even through those first four on the back nine, I think the scoring average will probably be one to one and a half under par on those holes.
"So losing a couple to the field there got me a little frustrated. If you kind of tap the brakes a little when the scores are going to be low you feel like you have to play catchup. Yeah, I just had plenty of looks. I didn't make many putts at all today."
K.H. Lee on putting improvements
"Today round is more difficult than yesterday, so I'm very happy today. I think my strengths going like iron play, so sometime iron play good but putting bad. This week iron play good and putting also good. So nice two rounds."
Hideki Matsuyama after just making the cut
"The front nine was a little spotty. Made some birdies, but a lot of bogeys. The back nine though I started hitting the ball really well, gave myself lots of chances, and just didn't convert. The wind started picking up and that made the course a lot more difficult than it was yesterday."
Lee Westwood (-9 after a R2 64) on why he entered this week
"Well, a lot of things went into the decision. I was coming over prior to this to see my daughter in Palm Beach Gardens and I wanted to watch a little bit of the Walker Cup. I've never been to Dallas. I've never played this tournament. I've never played at Colonial. So I thought maybe, you know, try a new experience still at the age of 48, and obviously right in the middle there is a PGA Championship and I didn't want to have three off or four weeks off and go into the PGA rusty.
"So this is ideal, I don't want to call it prep for next week, but I prefer to go into a Major championship being competitive the week before."
Burns continues hot play, Bryson's boom, Kuchar in control and Texans turn it on...
Sam Burns on fire
Bryson DeChambeau driving the par-4 14th
Kuchar's early charge
Texas trio dialed in