Indianapolis 500 practice: Gabby Chaves leads for Dale Coyne Racing

Chaves's fastest lap of 227.961mph came on the third of the 66 laps he ran during the six hours.

He did not have a drive for the first part of the season, but has replaced Luca Filippi at Coyne for the two Indianapolis events and finished 17th in last weekend's road course race.

"It's only practice but if feels pretty good," Chaves said.

"It's my first time on top of the charts here in an Indycar.

"I'm pleased with the work of the team and the performance of Honda. Overall I feel like I have a pretty strong package.

"This month for me started 10 days ago when I found out I had a ride so I'm really stoked to be here.

"To be this competition feels really good. Regardless of my results, I want to be in IndyCar. A good result will help."

Townsend Bell, a veteran of many one-off appearances for the Indy 500, was second for Andretti Autosport at 227.593mph.

Honda drivers swept the top four with Bell's team-mate Carlos Munoz third at 227.589mph and Chaves's team-mate Conor Daly fourth at 227.524mph.

Ganassi's Charlie Kimball was the highest Chevrolet driver in fifth place followed by defending Indianapolis 500 winner Juan Pablo Montoya and 2008 Indy 500 winner and four-time IndyCar champion Scott Dixon.

Three-time Indy 500 winner Helio Castroneves was eighth in a Dallara-Chevrolet followed by eight more Honda drivers.

All 33 driver/car combinations entered in this year's Indianapolis 500 ran on Thursday, covering a total of 2563 practice laps.

Rookie Spencer Pigot took to the track with just 16 minutes left after his Rahal Letterman Lanigan team prepared a new Dallara-Honda to replace the one he crashed at Turn 1 due to a puncture on Wednesday.

He ran one installation lap to make sure all the hoses and fittings were right before climbing out of the car and shaking all the crew members' hands.

"It was a lost 24 hours for me and the team and I had to thank them for the job they did," Pigot said.

"It's good to know that it wasn't a silly rookie mistake.

"The car was destroyed and I feel bad for all the boys that had to work hard and put the car back together.

"I was fine but those are the guys that had to suffer and put in the long hours.

"It's not ideal to lose the track time we lost this week with the rain and then the crash but it was good to get a shakedown lap today.

"We will do as many miles as we can on Friday. The car ran good before the crash."

THURSDAY PRACTICE TIMES