That fall, which Marquez struggled to explain after Sunday's race, denied him a seventh consecutive win at a track he's dominated, and dropped him from first to fourth in a suddenly crowded championship field.
It also elevated a new rider — race winner Alex Rins — into a group of title contenders within nine points of the top. MotoGP now heads to the heart of its schedule in Europe with its first stop May 5 in Jerez, Spain, where Rins is certain to get a hero's welcome in his home country and Marquez will have a lot of explaining to do.
"We made a mistake," Marquez said. "We are human." Marquez seemed a bit superhuman in winning five of the last six championships. But his miscue catapulted Ducati's Andrea Dovizioso to the top of the standings despite the Italian having an otherwise miserable weekend in which he expected to lose ground.
Dovizioso had won the season-opening race in Qatar, finished third in Argentina and came to Texas just four points adrift of Marquez in the championship. Dovizioso then failed to make the final round of qualifying and started 13th.
He had lost sight of Marquez on the track and in the standings until he zipped past the crashed Repsol Honda, and ended the race in a surprising fourth. "We have to be happy about fourth. If I had one half lap more to ride I would have probably finished on the podium. " Dovizioso said. "Marc lost a lot of points and that for the championship is important. I am happy to be going to Jerez."
So are the other riders between Marquez and the top. Yamaha's Valentino Rossi, the 40-year-old winner of seven series championships, and 23-year-old Rins, whose first victory in MotoGP made him an instant title contender in some eyes.
Rossi was impressed by Rins on Sunday. Rossi held the lead for seven laps after Marquez crashed, but couldn't hold off Rins for the victory. "It's a shame because I haven't won for a long time. But I'm happy because we were strong for the weekend and these points are important for the championship now that's its open," Rossi said.
"For sure (Rins) is an opponent for the title. He's not just one race," Rossi said. "He's always very fast in the race ... He rides very clever and he's very smooth with everything." Rossi hasn't won a race since 2017 or a season championship since 2009. He has consecutive podium finishes in the last two races and his legions of fans love to see him top the standings.
In 2017, he left Austin in first place but only made the podium twice the rest of the season as Marquez won the championship. "The second half of the (2017) season was as disaster," Rossi said. "But I love to race in Europe because I know all the tracks."