INDIANAPOLIS (Thursday, May 7, 2009) - Marco Andretti topped the first full day of practice May 7 at the Indianapolis 500. Andretti turned a best lap of 39.9152 seconds, 225.478 mph on the 2.5-mile oval.Thirty-one drivers combined to turn 2,199 laps in the first opportunity for all drivers to begin preparations for the race. Rookies and drivers needing a refresher at the Speedway practiced three hours May 5 but got less than an hour of practice time May 6 before rain washed out the remainder of the day. On Thursday, the track opened up more than two hours earlier than originally scheduled to make up for some of the lost practice time.Two-time Indy winner Helio Castroneves was second-fastest Thursday with a lap at 225.237 mph. Ryan Briscoe was third, defending race winner Scott Dixon fourth and 2007 winner Dario Franchitti fifth. The top 27 drivers were separated by less than one second.Ryan Hunter-Reay was involved in the only incident of the day when the No. 21 Vision Racing car did a half-spin exiting Turn 2 and hit the wall early in the afternoon. Hunter-Reay was uninjured.Six hours of practice are scheduled for Friday before the fastest 11 drivers lock in starting positions on Pole Day on Saturday.