With the Mid-Ohio Sports Car Course proving quicker with every passing minute, it was no surprise when the last man to start a flying lap - Britain's Justin Wilson - ended up topping the timesheets. It was a less happy session for Helio Castroneves, however, after he sprained his wrist in a collision with the back of Mike Conway's car 15 minutes from the end.
The one-hour early morning practice session was the only opportunity for the teams and drivers to get out on track before the all-important qualifying session for Sunday's Honda Indy 200 gets underway at 11am local time (4pm BST), so it was no surprise to see 13 cars - over half the total field - exiting pit road as soon as possible.
The early shakedown runs tended to be around 1:17-1:18s as the drivers started working at paring the times back down to the levels seen on Friday afternoon which were some ten seconds quicker. Marco Andretti led the way, with a 1:13.6661s on his third flying lap which he promptly lowered to 1:12.8526s next time around and then to 1:11.8578s ahead of KV Racing duo Tony Kanaan and Rubens Barrichello before pitting ten minutes into the session.
Josef Newgarden, Graham Rahal and James Hinchcliffe picked up the baton after that, but it was championship leader Ryan Hunter-Reay who finally deposed Marco from the top spot with a lap of 1:11.4729s four minutes later before his time was shaved by a further tenth as Newgarden went top.
The next surge was heralded by JR Hildebrand going top with a 1:10.3409s a tenth ahead of the latest laptimes from Scott Dixon and Marco Andretti at the 20-minute mark. Marco pushed on and was the first man under the 70s time, trading the top of the timesheets back and forth with Dixon until he pulled out a half a second on the Kiwi with a lap of 1:08.8560s.
As they pitted, the top time then came under a combined assault from two of the Brazilians in the field - with Penske's Helio Castroneves setting a new target time of 1:08.6620 just 0.0234s ahead of Kanaan - and then from France's Simon Pagenaud who lowered the time to 1:08.5081s ahead of Newgarden. But as the halfway point of the session was reached, it was Castroneves back on top again with a 1:07.8489 almost three tenths faster than Dario Franchitti who had been the last car to take to the track for the session.
Will Power shouldered his Penske team mate aside a minute later with a 1:07.7155s, and then Hildebrand demonstrated how much faster the track was getting with every passing minute by going to the top again with a 1:07.5763s promptly bested by Ryan Briscoe's effort of 1:07.1072s.
After a brief pause for set-up tweaks, more fastest laps came thick and fast: Sebastien Bourdais, James Hinchcliffe, Scott Dixon and Dario Franchitti all went top for a time before Will Power went fastest with a lap of 1:06.7152s just before the red flag came out with 15 minutes to go.
The stoppage was for an on-track incident between Helio Castroneves and Mike Conway, the left-front of the Penske car running into the right-rear of the slow AJ Foyt Racing car. It appeared that Conway had been trying to allow Castroneves past at turn 2, but the two had then been the victims of an unfortunate miscommunication.
It seemed a minor matter, but Helio was left urgently gesticulating to the track workers and calling for help, indicating a problem with his left hand which had likely been caught by the violent snap of the steering wheel in the contact. Castroneves was taken to the medical centre for assessment, with concern that he might have done some serious injury to his wrist. He emerged later still in pain and with his hand heavily bandaged, no bones broken but with a painful sprain. He insisted that he'd still be in the car for qualifying and the race, however, and the medical team confirmed that he was cleared to continue driving.
The session resumed with a little over ten minutes remaining, but Castroneves' accident appeared to have unsettled pit lane an broken the momentum and it took several minutes before Dixon was finally able to usurp Power from the top with a lap of 1:06.5704s. A flurry of fast final laps was improvements from Hinchcliffe, Power and Pagenaud were finally all trumped by Justin Wilson posting a 1:06.3018s just after the chequered flag had dropped.
Full practice 2 times