It took shadows to let performance begin to shine through Friday at zMAX Dragway for the opening day of the 18th annual Fitzgerald USA Thunder Valley NHRA Nationals at Bristol, Tenn.

In the opening late afternoon session, once again, nitro crew chiefs couldn’t connect with the knuckleballs thrown their way by NHRA’s new 2018 less sticky traction preparation.

An 84-degree sunny day that heated the track to 134 degrees with an adjusted altitude of over 4,000 feet baffled the greatest minds in drag racing.

In the first session, Bob Tasca and his Ford Motorcraft Mustang was the quickest with a run of 4.157 seconds at 300.26 mph. Points leader Courtney Force was the fourth best at 4.277.

In the second session, Force and the Advance Auto Parts Camaro team had the field covered like they have through nearly all of the Mello Yello Series events this year.

Force holds the provisional pole with a time of 3.993 at 325.92 and is in position to earn her seventh pole in 11 events, and four of the times when she started No. 1 she went on to win the Mello Yello title.

“It was a great run. It was haulin’ the mail down there,” said points leader Force. “It was a little bumpy down there so I had my hands full.

“I want to go back (to the pits) and critique the run. I got it a little outside (the traction groove) but it stuck. That’s all that mattered.

“Job well done by (crew chiefs) Brian Corradi and Dan Hood and all my guys. Great start to the weekend.”

In other Mello Yello categories: Tennessean and defending event champ Clay Millican is No. 1 with a time of 3.817 (322.88) in Top Fuel and Greg Anderson leads Pro Stock with a time of 6.674 (205.35).

And it really is supposed to heat up for Saturday’s final qualifying sessions at 1 and 3:30 p.m. (EDT) when it’s forecast to be in the low 90s with similar conditions predicted for champion eliminations.

“I think it will be quite a bit hotter tomorrow so we’ll see how we do in the heat,” she said. “Tomorrow is way more important than today because the heat will be like what it’s supposed to be on Sunday.”

Through 10 races the seven-year pro has never qualified lower than No. 4.

Her win a week ago near Richmond, Va., was her third in four national events and her fourth of the season matching her career best season.

“This is just the beginning of the season and we just have to maintain our focus. So much credit goes to my team and the job that they have done. I am trying to keep up with them and perform well as a driver.

 “Right now it is great but we really have to keep it all year long if we want to end up on top at the end of the season.”