With just one race to go before Red Bull's self-imposed deadline to confirm their 2026 driver lineup, Lawson was bested by Yuki Tsunoda, twice in two days, even after outqualifying him on both occasions.
Now, heading to Mexico, there is everything to play for.
Here's what we learned in Austin:
This year has been a rough one for Tsunoda. A dream move to Red Bull has, for the most part, turned into a nightmare.
In the same car, he trails teammate Max Verstappen by 278 points. Last year, Sergio Perez finished the season 285 points back, and was sacked as a result.
But, over the past two days, Tsunoda was easily among the standouts. In the sprint race, he went from 18th to seventh, courtesy of an opening lap maelstrom which took out both McLarens.
Then, after qualifying 13th in the grand prix - one place behind Lawson, Tsunoda was smart to remain wide going into turn one, and climbed up into the top 10 as a result.
It's a sign of things that Tsunoda finishing in the points is considered an achievement - his teammate has now won five races this season after all.
But in the context of how difficult that RB21 has been to drive all year, the Japanese driver is performing at the right time - a skill on which any driver's career should be built on.
Red Bull team principal and chief executive Laurent Mekies has said the team's drivers will be decided by more than just one race weekend's results.
And with that in mind, it's hard to know exactly where any Red Bull driver stands who isn't called Max Verstappen. What is unchanged for Tsunoda, though, is that he is the outsider in Racing Bulls' 2026 equation.
With his own future on the line, considering the lack of available seats elsewhere on the grid, Tsunoda's actions on Sunday in particular did a lot of talking.
Even after finishing seventh in the sprint, qualifying saw Tsunoda accuse Lawson of deliberately driving slow in front of him, and therefore sabotaging his attempt to start higher up the grid.
Speaking after qualifying, Lawson said: "I have no idea what he's on about."
Interestingly, Lawson wasn't the only driver to have been in front of Tsunoda. Alpine's Pierre Gasly could have easily been accused of doing the same thing.
The exception there, though, is that Gasly isn't fighting Tsunoda for a 2026 Racing Bulls seat.
Tsunoda has always been known to be petulant. But that incident altogether showed that he's feeling the heat from Lawson's challenge, and knows that results themselves might not be enough to save his place on the grid.
Considering how you choose to read it, Red Bull might have already confirmed its plan for Lawson in 2026.
While the formal decision over driver lineups won't come until after the Mexican Grand Prix at the earliest, the cat might already have been let out of the bag.
In the lead up to Austin, Lawson was heavily featured in promotional work for Ford, used throughout the US Grand Prix.
Ford is more than just a Red Bull commercial partner, it will be making both teams' engines in 2026.
By making use of Lawson in a promotional capacity, before they've officially launched their 2026 cars, Ford has effectively shown that the Kiwi's image is one it wants to build its and Red Bull's brand around as the American manufacturer prepares to enter the sport.
Yes, no decision over Red Bull's lineups have been made, and won't be revealed before the end of October at the earliest.
But, if Lawson isn't going to continue into 2026, this is a very strange move on Red Bull and Ford's part.
Amid the Lawson-Tsunoda battle for a 2026 seat, it's easy to forget that Red Bull are still to announce - publicly at least - who'll take the spot in their top team.
While it's almost guaranteed that Isack Hadjar will step up from Racing Bulls, this weekend's displays were far from convincing.
The sprint race saw him qualify 12th, before dropping to 18th and only recover once cars in front of him were forced to retire, and therefore finish where he started.
Then, in qualifying, he lost control at turn six, crashed, and red-flagged the session before he could even set a timed lap.
To cap it all off, starting at the back of the grid in the grand prix, the Frenchman was shown a black and white flag for track limits just six laps in, and crawled to 16th as the last-placed of the four Red Bull cars.
Hadjar struggling at Austin is understandable. The Circuit of the Americas doesn't feature on the Formula Two calendar, making this weekend Hadjar's first taste of racing there.
That, though, shows Red Bull the huge risk in promotion after just one season.
The same move was made with not only Lawson, but Pierre Gasly and Alex Albon, all of whom were discarded. In fact, the safest move Red Bull made was signing Perez from Racing Point, even if it did end in tears.
If Red Bull are serious about mounting a challenge for the constructors title in 2026, they might be wise in understanding Hadjar will still need time to get to grips with the reality of being a Formula One driver.
Just like we did to end 2024, we now head to Mexico with Red Bull's driver lineups front of mind.
Last year, it was Lawson v Perez, a match-up that the Kiwi ultimately won. This year, it's Lawson v Tsunoda v Hadjar.
Regardless of whether it's the right call, considering Red Bull could do a lot worse than keep their two teams' pairings as they are for another year, this is the reality that the team wants to be in.
Despite struggling in Formula Two, Arvid Lindblad is all but locked in for promotion, and will squeeze one driver out of a race seat altogether.
Now, all we can do is wait and see what happens over the coming week at the Autodromo Hermanos Rodriguez