Fernando Alonso retires from Indy 500 as Honda engine fails

Fernando Alonso's Indy 500 dreams ended in smoke after his Honda engine failed with just 21 laps to go.

Victory went to ex-F1 driver Takuma Sato, one of Alonso's team-mates, and he becomes the first Japanese driver to win the race.

Alonso was constantly involved in the fight for the lead during the opening exchanges on Sunday and headed the field when the red flag was thrown following a horror crash between Scott Dixon and Jay Howard.

Both drivers were cleared by the medical centre, but Dixon did later return for a protective boot.

When Alonso finished the race, he had the fastest average lap time of any driver underlining the pace he had shown.

"I felt the noise, the engine friction and I backed off and saw the smoke. I think we deserved to at least finish the race. Who knows what position we could have been?" Alonso told American broadcaster ESPN.

"The whole day has been a very nice experience - the racing was fun, we were leading the race for a couple of laps... it was a nice surprise to come here and be able to be competitive."

Despite the disappointment, Alonso took time after the race to thank the media and even got a taste of milk, usually reserved for the race winner.

With Alonso out, focus switched to Max Chilton, who had run an offset strategy and found himself in the lead of the race having started in 15th.

But with just seven laps to go, the Briton lost the lead, eventually finishing in fourth spot.

"I knew I was strong out in front, we knew that all week, but I struggled in dirty air and starting 15th, I was over a lap behind after the first stint," said Chilton.

"I had the car to do the job, the issue was the cars in second and third could tow each other up to me and get past. If they didn't have a car to work with, I think I would have stayed out in front like I did for most of the race because no-one seemed to be able to draft up to me."

Ahead of Chilton and taking top rookie honours was Dubai-born British driver Ed Jones, who finished third.

The battle between Sato and Team Penske's Helio Castroneves went right to the wire, with the pair exchanging places on a lap-by-lap basis as the race neared its conclusion, but it was ultimately Sato who made the decisive move to hold on for the win.