Scott Dixon moved to the top of the timing screens at the end of Friday's practice sessions at the 13-turn, 2.258-mile Mid-Ohio Sports Car Course ahead of this weekend's Honda Indy 200.
The Ganassi driver, who has won here five times in the last eight outings including last year's race at Mid-Ohio, set a time of 1:05.9645s (123.230mph) near the end of the second of the day's two 75 minute practices.
CLICK: Full Friday practice 2 times from Mid-Ohio Sports Car Course
Dixon was within six tenths of a second of matching the track qualifying record set by Dario Franchitti in 1999 and matched by Gil de Ferran in 2000. It put him a slender 0.0545s ahead of KVSH Racing's Sebastien Bourdais, last year's pole sitter and race runner-up who had earlier topped the morning session.
"We went through a few different set-up changes just to try to find our groove, but overall the car was pretty quick,” said Dixon. "We'll hopefully carry some speed into [tomorrow's qualifying session] and try to start up front."
Despite being bumped off the top spot at the end of the day, Bourdais was still feeling confident about the performance of his car heading into the weekend.
"It is always very tricky at the beginning of the session, but the Hydroxycut machine seems to be strong whether it's early, late, new tyres, old tyres," he said.
"We just have to find a little bit of front grip," he continued, pointing out that while the car was looking strong on the harder primary Firestone tyres they still had a way to go to get the speed on the softer options.
"One thing that has developed for us this year is we never seem to have issues making the car work on the black [primaries], but we have a problem on the red tyres," he said. "If the Firestone reds behave for us, I think we will have a shot at the pole."
Penske's Will Power, who had been second behind Bourdais in the earlier session, was bumped down to third place in the afternoon ahead of Rahal Letterman Lanigan Racing's Graham Rahal and AJ Foyt Racing's Takuma Sato, meaning that the top five were from five different teams and the latter two both from the Honda contingent.
Dixon's Ganassi team mate Tony Kanaan was sixth fastest ahead of an impressive showing from Sato's team mate Jack Hawksworth. Rounding out the top ten were Marco Andretti (Andretti Autosport), Josef Newgarden (CFH Racing) and Ryan Hunter-Reay (Andretti).
All but four drivers improved their times in the afternoon, the exceptions being Newgarden, Carlos Munoz (Andretti), Simon Pagenaud (Penske) and Rodolfo Gonzalez (Dale Coyne Racing). Gonzalez remained bottom of the time sheets for the day in his return to the #18 after sitting out the last two oval races while Pippa Mann took over the race seat. In the afternoon, he finished 2.2223s adrift from Dixon's session-best time.
It was also not the best of days for championship leader Juan Pablo Montoya, who ran only 12 laps in the morning because of an alternator issu and was then only 21st in the afternoon with a best lap of 1:06.9930s after 21 laps in the afternoon.
The session had been two early red flag interruptions for off-track excursions onto the dirt and grass for Newgarden's team mate Luca Filippi, the former GP2 driver finding Mid-Ohio a tough track to tame this year.
Tristan Vautier also went off-roading in the afternoon and damaged the bodywork on the Dale Coyne #19 in the process. In the morning, both Tony Kanaan and Simon Pagenaud had also emphatically exceeded track limits and gone onto the grass to cause red flags but with no significant longer term harm done in either case.
Friday's sessions saw the début of new LED panels on the side of all 24 cars taking part which will be used to share real-time position information of each entry with spectators. The panels had originally been scheduled to be introduced at the Grand Prix of Indianapolis, but pre-event testing had shown that the technology needed further testing and development before it could be properly rolled out.
The drivers now have one further 45-minute practice on Saturday morning at 10.45am (3.45pm BST) ahead of qualifying which takes place at 3.15pm.
The teams will also have a half hour morning warm-up on Sunday morning at 9.45am (2.45pm) ahead of the 90-lap, 203.22-mile race which gets the green flag just after 2pm (7pm) on Sunday evening.
See full Friday practice 2 times from Mid-Ohio Sports Car Course
See combined Friday practice times from both sessions at Mid-Ohio