Loek Hartog laid down the quickest time of the Porsche Carrera Cup North America opening practice at Road America on Thursday, putting local team Kellymoss atop the time sheets.
Hartog, the Pro class championship leader, took his No. 24 Porsche 911 GT3 Cup race car to a best lap of 2:09.706
It was 0.093 seconds quicker than Dan Clarke in the debuting No. 64 Era Motorsport Porsche, who posted a flyer late in the session.
Ryan Yardley ended up third in the No. 78 Topp Racing Performance entry, with Zachary Vanier and Elias de la Torre completing the top five, both in JDX Racing Porsches.
Efrin Castro led the Pro-Am ranks in his No. 65 Kellymoss Porsche, while Scott Blind was quickest of the Masters competitors aboard the No. 45 Rukus Racing entry.
The session, originally scheduled for 40 minutes, was extended by five minutes following an accident by the No. 26 ACI Porsche of Roberto Tutino, who went off in Turn 11 and required track repairs with ten minutes remaining.
Track action resumed with seven minutes left on the clock, which saw a notable improvements by Clarke and Yardley.
The second practice of the weekend is scheduled for 9:35 a.m. CDT, followed by qualifying at 5 p.m.
RESULTS: Practice 1