Stewart-Haas Racing driver Daniel Suarez jumped to the top of the leaderboard with his second-to-last lap in opening practice at Pocono Raceway.
At 171.217 mph (52.565 seconds), Suarez paced the first of two 50-minute practice sessions slated for Friday. He and Ryan Blaney — second quick at 171.090 mph — were the only two drivers to crack 171 mph.
Completing the top five was Alex Bowman at 170.338 mph, Kyle Busch at 170.290 mph, and Brad Keselowski at 170.226 mph. Busch won the most recent race at Pocono last July.
Denny Hamlin (170.029 mph), Joey Logano (170.026 mph), William Byron (169.985 mph), Clint Bowyer (169.952 mph), and Martin Truex Jr. (169.927 mph) were the rest of the top 10. Truex, who enters Pocono off a win last weekend in the Coca-Cola 600, is the defending race winner.
Kevin Harvick was 15th fastest at 169.651 mph and ran the most laps in practice with 29.
Matt Tifft and the No. 36 Front Row Motorsports team were the only ones who had to serve a practice hold during the session. The 15-minute penalty was a result of the team failing pre-race inspection twice last weekend. Tifft wound up 31st on the speed chart with a lap of 165.186 mph.
There were no incidents in opening practice.
UP NEXT: Final practice at 4:05 p.m. ET.