Only 14 of 23 starters finished Sunday’s SRO GT World Challenge America three-hour race at Road America. TR3 Racing was not just among them. They won.

First-year driver Brayton Williams and co-driver Daniel Morad brought the No. 9 TR3 Racing Mercedes-AMG GT3 home with a 6.433-second margin in Pro-Am, finishing third overall in a race that chewed through nearly 40 percent of the field. It was the team’s first endurance victory and only their third GT World Challenge win ever.

The script was straightforward. Williams, a rookie still building seat time, delivered what both he and Morad called the best opening stint of his short career. He survived a snap through Road America’s high-speed kink, kept the car clean, and handed it over in striking distance.

Morad, his coach and co-driver, took over and muscled into the lead with roughly 40 minutes remaining. He never gave it back. “If you are not first you are last, and on Sunday we were first,” Morad said. “I never shy away from a good old street fight.”

The win didn’t happen in isolation. Mercedes-AMG customer teams ran the table at Road America in a way no other manufacturer managed. The No. 34 JMF Motorsports entry of Michai Stephens and Mikael Grenier finished second overall and second in the Pro class, preserving a three-point championship lead with two rounds left.

The sister No. 27 JMF car of Jason Daskalos and Philip Ellis salvaged a top-five Pro-Am finish and seventh overall after an engine swap wiped out nearly all their practice time. Mercedes-AMG was the only manufacturer with multiple entries to get every car to the checkered flag. Two of their three cars landed in the overall top three.

That durability stat matters more than any single trophy in a race this brutal. When attrition thins the herd by nine cars, finishing is a competitive act. Finishing with all your entries intact, in a field where rivals couldn’t manage the same, tells you something about the platform and the teams running it.

Williams credited heavy simulator work with Morad for accelerating his development. Morad praised his young teammate’s discipline. “We are making all of the typical mistakes on the simulator,” he said. “Understanding how to actually execute these moves in the virtual world avoids the detrimental outcome at the track.”

In the GT4 ranks, the weekend was rougher for Mercedes-AMG squads. JMF Motorsports driver Marc Miller walked away from a heavy multi-car crash on Saturday. But Am class entrants Eddie Killeen and Laura Hayes picked up the pieces, running the No. 37 Dome Motorsport Mercedes-AMG GT4 to a season-best second place in wet conditions during Saturday’s sprint.

Hayes, who was driving a Mercedes-AMG GT4 in the rain for essentially the first time, wanted one more lap. “I think we could have won it,” she said.

The championship picture tightens heading to Barber Motorsports Park later this month. Grenier and Stephens hold a slim three-point Pro class lead. Daskalos admitted his title hopes now require winning both remaining races. The finale at Indianapolis carries double points.

Barber is a track where multiple Mercedes-AMG teams have shown pace before. Grenier called it “a good track for us.” Daskalos was more direct: “I am really good at Barber and the Mercedes-AMG GT3 is really good at Barber.”

Two rounds remain. Three points separate the leader from the field. And nine cars that started at Road America never saw the finish.