Dario Franchitti staved off Will Power on a road course, with a time of 1:19.4269s managing to put the Scot just over a tenth of a second faster than the Australian at the end of the Friday afternoon practice session for Sunday's Indy Grand Prix of Sonoma at Infineon Raceway in California.
"There is still room to improve, but I am happy with the performance today," said Franchitti. "It feels like there is some more grip compared to the test here [held last week] and I hope that the track just continues to get better as the weekend progresses."
"We are very close to getting the car where we need it," said a confident Power. "It just comes down to sorting out the fine details. The team will try to think about the changes we can make tonight and see where we can go tomorrow."
Helio Castroneves and Scott Dixon finished third and fourth in the timesheets on the 12-turn 2.52-mile natural-terrain course, meaning that the top four positions were all held by the last four winners at the venue: Will Power is defending champion here, but Franchitti took the honours in 2009, Castroneves in 2008 and Dixon in 2007.
After her big press announcement on Thursday, Danica Patrick - never a natural road course racer - returned to the cockpit with Andretti Autosport and finished the practice session in a disappointing 26th place. Her team mates Ryan Hunter-Reay (12th), Marco Andretti (15th) and Mike Conway (18th) also had a rather average Friday at the races.
"It was a pretty challenging first day for us," admitted Hunter-Reay. "We'll have to change a lot of the settings for Saturday. It was different from last week's test. We felt the car was okay last week. That wasn't the case today. Just overall lack of grip."
A number of drivers struggled particularly with the turn-in to the chicane, culminating with spins for Scott Dixon and then James Hinchcliffe two minutes from the end of the practice session that brought out a full course caution. After race control allowed a brief extension to permit cars one final fast run, a large number of cars then proceeded to run straight off onto the dirt again before returning to pit road.
Alex Tagliani had earlier caused a full course caution, a little over nine minutes from the end of the initial 45-minute part of the 75-minute Friday practice reserved for rookies and drivers outside the top ten. He was uninjured after running off at speed into the tyre barrier out of turn 3.
The session saw current Renault Formula 1 test driver Ho-Pin Tung take to the track with Dragon Racing and finish the day with a very creditable 17th position. Tung was reunited with Dragon after he impressed them at Indianapolis in May, and the team struck a technical support deal with Sam Schmidt Motorsports to run him this weekend on the California road course under the Schmidt Dragon Racing banner - which should see him become the first Chinese driver to make an IndyCar Series start.