JK Vernay won on his Firestone Indy Lights debut on Sunday dominating the rain-soaked Grand Prix of St Petersburg.

Vernay, who started on the outside of the front row, held off fellow series rookie Jan Heylen on a lap 29 re-start in the #7 Lucas Slick Mist/Sam Schmidt Motorsports car and went on to an 11.2338-second victory in the shortened (from 45 laps to 35) race on the 1.8-mile, 14-turn temporary street circuit.

"I am really happy today," said Vernay. "It was a very good weekend since the start of practice. I didn't know this track, so I had to learn a lot. It helped with the work I did with my team. We had a great set-up on the car. Practice after practice, I was pushing more and more, and we were there, so it was good. It was hard not to have the pole, but I was very careful on the first lap. I didn't want to crash at the start of the race. It was great to win in my first weekend in Indy Lights."

Cars started the race on slicks, with pole sitter James Hinchcliffe punted in turn 1 of the first green flag lap by the #49 Sam Schmidt Motorsports car driven by Philip Major. He was looking to make a big move on the inside (having started ninth) but braked too late to make the sharp right-hand turn.

Sebastian Saavedra emerged as the leader - until he spun in turn 4 of lap 5. Vernay was in position to avoid the mid-track mess and took the lead through a red flag at the completion of lap 6 for crews to change to rain tyres.

A full-course caution on lap 26 when the #29 Bryan Herta Autosport car driven by Saavedra made contact with the tyre barrier on the exit of turn 7 was the lone challenge for Vernay to overcome.

Heylen, who competed in nine Champ Car races in 2007, couldn't overtake Vernay on the re-start with time running out.

"The conditions were difficult, especially in Turn 1. I think we made a bad set-up on the car. It was too bad I couldn't give my good friend Stefan a run for his money during the race," said Heylen. "It was nice being back in the car though. I have not been racing for almost three years. So it's good to be back, and I really hope that I can race in some more this year. I very much enjoyed it."

Stefan Wilson meanwhile drove from the 14th starting position to finish third in the #28 Bryan Herta Autosport car and Charlie Kimball tied his series-best finish of fourth in the #26 AFS Racing/Andretti Autosport car.

"I want to thank all my crew guys for working hard late last night," reflected Wilson. "I started the weekend off pretty happy with my car. I was position one in practice and position three in the race. I thought it was going to be a good weekend, but it was a bit of a roller coaster in qualifying. We had a small mistake and it cost me a great amount, and I had to start from the back of the field in the race.

"That quickly changed when the rain started to come down. People started going off the road as it was pretty slick out there. The white lines on the runway were treacherous, and a lot of people started making mistakes in front of me. I was in the P5 position, and after we went green after the break, I started moving up."

Gustavo Yacaman, who started 10th in the #10 Cape Motorsports with Wayne Taylor Racing car, advanced five positions, while Martin Plowman finished sixth in the #27 AFS Racing/Andretti Autosport car. James Winslow and Jonathan Summerton finished seventh and eighth, respectively.