Chip Ganassi driver Sage Karam has recorded the fastest lap on the first day of practice for the Indianapolis 500.

In a session interrupted by rain, Karam used a slipstream to hoist the fastest lap in 225.802mph (363.39km/h) in the closing minutes as preparation for the 200-lap May 24 race began.

Karam’s effort overshadowed Scott Dixon who held sway at the top with an sizzling 225.293mph (362.57km/h) which was established without a tow from other cars.

Ganassi drivers filled the top three places with Tony Kanaan 225.217mph (362.45km/h) edging out Marco Andretti with the top four the only runners to better the 225mph mark.

Karam put his run in perspective by saying: “It’s only the first day, so it’s not about how fast you are today.

“It’s about how fast you are on Sunday in two weeks. It definitely feels good though. It’s the first time I’ve ever been P1 at the Speedway so, you know, it’s a good feeling.”

JR Hildebrand, Ed Carpenter, Carlos Munoz, Justin Wilson, Takuma Sato and Josef Newgarden completed the top 10.

The powerhouse Penske operation saw IndyCar Series leader Juan Montoya turn only three laps under full pace while team-mates Helio Castroneves and Will Power completed only one lap each.

The fourth Penske runner, Simon Pagenaud, was 19th fastest after turning 31 laps of the 4km super speedway.

Practice continues each day through to Friday.

See below for full opening practice results