INDIANAPOLIS -- This was exactly what Michael and Marco Andretti had talked about: down to the end of the Indy 500, father and son running 1-2.
Then, with one dazzling last-second move, Hornish whipped around the 19-year-old rookie on the final straightaway and won the second-closest Indy ever, by 0.0635 seconds, a little more than a car length.
Michael Andretti, who came out of retirement at age 43 to race with his son for another try at racing's biggest prize, was third, 1.0087 seconds behind.
A happy ending at last for Hornish, who's had his own run of bad luck here, but just another chapter in the Andretti family's hard-luck drama that dates back nearly four decades.
"Second place is nothing," Marco said. "They don't remember people who finish second here. They really don't. You gotta take advantage of every shot. How many times did my dad finish second? He never won it and neither did I."
Hornish overcame a disastrous mistake to finally win Indy in his seventh try: Late in the race, he left his pit with the fuel hose still connected, and the ensuing penalty put him down a lap. But his team stayed cool, and Hornish found himself trailing only the Andrettis and Scott Dixon when the green flew with four laps to go.
The newest Andretti at the Brickyard had brought the crowd to its feet by passing his father for the lead with three laps to go. Hornish followed and took aim at the kid, second youngest ever to drive at Indy.
Hornish tried to dive inside on the third turn of the next-to-last lap and the two almost collided, forcing Hornish to fall several car lengths back.
He figured that was his last chance.
"Thank goodness," he said, "it's 500 instead of 497½."
Marco thought so, too.
"I thought I had won it," he admitted.
But Hornish, who failed to finish his six previous Indys, mounted one final charge.
He caught up on the final lap, and Andretti, in only his fourth IRL IndyCar Series start, couldn't hold on.
"I think I could have moved to the inside, but at that time he would have already made his move and it would have been a big one," Andretti said. "I wouldn't have done anything different except for coming off the last corner. ... He just had that speed and I don't know where it came from."
Hornish swung low, pulled alongside and nosed ahead at the checkered flag. In 90 runnings of the Indianapolis 500, the only closer finish was in 1992, when Al Unser Jr. beat Scott Goodyear by 0.043 seconds.
Hornish's mistake in the pits might have cost him a shot at the victory if his team had panicked -- but Hornish drives for Marlboro Team Penske, the most successful in the sport's history.
"I said, 'Go! Go! Go!' and the fuel probe wasn't completely out," said Roger Penske, who now owns 14 Indy victories, nine more than anyone else. "That was my mistake. But instead of everybody falling over and folding their tent, we said, 'What can we do now?' "
What they did was use the penalty -- a green-flag drive through the pits on lap 163 -- to add a few gallons of fuel for an all-out run to the finish.
Asked what he was thinking when he saw the hose tearing off the car, Hornish said: "Probably the first thing that came to my head is, 'I can't believe this is happening.' The second thing that came to my head is, 'The last two years I put the car into the wall, so I better shut up and not say anything.' "
After he won, a choked-up Hornish lay on the track and kissed the yard of bricks at the finish line.
"I keep getting emotional about it," he said. "I got to try to figure out how to get through all this stuff without starting to cry and not be able to talk. I don't think I'll ever be able to fully appreciate what it means or be able to put into words what it means to me."
Despite the thrilling finish that introduced Marco Andretti as perhaps the sport's newest young star, the third-generation driver wasn't satisfied with second place.
"Man, I don't want to wait for next year," he said. "It's a bummer. Woulda, coulda, shoulda. I mean, second place is nothing."
Michael and Marco -- who's only had his driver's license for a few years now -- hooked up early and stayed close to each other almost all day, often nose-to-tail and rarely with more than a car or two in between.
Michael Andretti was obviously proud of his son.
"I just knew he was going to surprise a lot of people," Michael said. "He didn't surprise me. I was just a little surprised by how fast he got here."
It was one of the hottest days in Indy history, with the temperature reaching 89 degrees, and the action on the track was just as heated.
Defending champion Dan Wheldon dominated most of the race, leading 87 of the first 100 laps and 148 overall, but a tire puncture forced him to pit earlier than planned.
Wheldon wound up fourth, followed by Tony Kanaan, Dixon, Dario Franchitti and last year's rookie sensation, Danica Patrick, the only woman in the 33-car field.
Patrick ran a strong, clean race, despite struggling all month to find speed. She started 10th and moved up as high as fifth before falling back when she was caught in the pits on a yellow flag.
"I should be happy, right?" said Patrick, who clearly wasn't. "I didn't stall, I didn't spin, I didn't do anything stupid."
Michael Andretti led four laps, taking over when teammates Kanaan and Franchitti pitted on lap 193. But he would only add to the dubious distinction as the driver who's led more laps here than any other non-winner -- 430 -- and he was pretty sure he wouldn't win this time, either.
"I knew I didn't have the speed and I saw Marco making a run at me," he said. "I started to move over to do a little block, but he was really moving and I decided to let him go. I thought I could help him out by blocking Hornish a little, but he got by me a little too quick."
Hornish, who was fastest here all month and easily took the pole, led only 19 laps.
At that moment, Michael Andretti, about a third of the straightaway behind the leaders at the finish, thought for a moment that his son had won.
"I really put my hand in the air, thinking he won the race," Michael said. "I couldn't believe it. It's like -- where did Hornish get that speed? It's like he had a button in there to push.
"It's a heartbreak, another one," he said. "But in a couple of days, I'll probably sit back and think, 'Oh wow!' I thought he had won. It was a fairy tale, a dream."