Marcus Armstrong wasn’t feeling great Friday, but his race car was at full strength during the first practice for the XPEL Grand Prix at Road America Presented by AMR.

Armstrong, suffering from the flu, produced the quickest time of the opening practice for the NTT INDYCAR SERIES race, leading a 1-2 by Meyer Shank Racing w/Curb Agajanian with a best lap of 1 minute, 44.2714 in the team’s No. 66 Honda. 2026 Indianapolis 500 presented by Gainbridge winner Felix Rosenqvist was second at 1:44.3501 in MSR’s No. 60 Honda.

SEE: Practice Results

“It’s good to top the Friday 500 here in Elkhart Lake,” the wry Armstrong said. “It’s OK. The car feels good – that’s the main thing. I’m as sick as a dog. I don’t feel great. At least I’ve proven to myself I can still be fast with two hours of sleep. It’s going around – flu season, isn’t it?

“It’s good that you roll out on blacks (Firestone Firehawk primary tires) and you’re fast, and you put reds (Firestone Firehawk alternate tires) on and you’re fast. And we didn’t do anything spectacular. I don’t think I did a perfect lap, either, so it’s nice Felix is right up there, too. It’s all good.”

Series leader and reigning Road America winner Alex Palou was third at 1:44.3659 in the No. 10 DHL Chip Ganassi Racing Honda. Palou, who leads runner-up Kyle Kirkwood by 49 points, has three career victories in seven starts at the 14-turn, 4.014-mile road course.

“This place, it’s so enjoyable as a driver, especially when you have a fast car like we seem to have today,” Palou said of the longest track on the schedule. “It’s hard work; it’s never easy to put up a lap together here at Road America, but it feels so fun.”

Arrow McLaren teammates filled the last two spots in the top five. Pato O’Ward was fourth at 1:44.3688 in the No. 5 Chevrolet, while Nolan Siegel enjoyed perhaps his best session of the season in the No. 6 Chevrolet by rounding out the top five at 1:44.4328.

Kirkwood, the only driver within a race’s worth of points of Palou, was 15th at 1:45.0332 in the No. 27 Sam’s Club Honda of Andretti Global.

Two rookies ended up in the top 10. Caio Collet was the quickest first-year driver, sixth at 1:44.4651 in the No. 4 Combitrans Amazonia Chevrolet of AJ Foyt Racing. Mick Schumacher produced arguably his best session since qualifying fourth in March for his first oval race at Phoenix Raceway, ending up eighth at 1:44.7864 in the No. 47 ENVE Honda of Rahal Letterman Lanigan Racing.

There was one incident that triggered a red flag. Sting Ray Robb was unhurt after spinning on the exit curb at Turn 14 and hitting the outside wall, bending the left front suspension and rear wing of his No. 77 Juncos Hollinger – Goodheart Chevrolet.

Up next is practice at 11 a.m. ET Saturday, followed by NTT P1 Award qualifying at 2 p.m. ET. FS1, FOX One and INDYCAR Radio powered by OnlyBulls are broadcasting both sessions live.

Live coverage of the 55-lap race starts at 2 p.m. ET Sunday on FOX, FOX One, FOX Deportes and INDYCAR Radio powered by OnlyBulls.