"I am not a driver anymore," the 26-year-old Argentine said. "I just retired 10 minutes ago."
Holding a 5-second lead with less than six laps to go in the 35-lap race, Guerrieri failed to properly execute Turn 3. The rear of his Lucas Oil/Sam Schmidt Motorsports car hit the inside of the wall and Guerreri's car was unable to continue.
Gustavo Yacaman of Colombia eventually won, but not after another driver holding a sizeable lead, Anders Krohn of Norway, missed making Turn 1 later on in the race and fell out of contention. He finished sixth.
It was not only Yacaman's first victory on the Indy Lights circuit, but the first time the 30-year old had ever led an Indy Lights race at any point.
"They've been waiting three years for this. We've worked so hard," Yacaman said of Team Moore Racing. "I've been training 20 hours a week. This is the most physical track I've ever driven. It pays off when the most physically fit driver in the series wins the race."
Both Guerrieri and Yacaman attributed their late race mishaps to mental errors.
Krohn, a 23-year old Norwegian known on the circuit as "The Viking" was as disconsolate as Guerrieri about his grievous mental error. It came after a restart following Guerreri's car dropping out.
"I got a fantastic re-start and was leading by 10 car lengths on the straight-away," Krohn said. "It was a totally unacceptable mistake. I'm just heartbroken. We've been busting our hump all year without any breaks and when we finally get a break, we mess up. We had it in the bag and I messed it up."
Asked to explain what happened — it looked like he was making the wrong turn up Calvert Street — the Indy Lights rookie said, "I braked too early, the front of the car bottomed out and both front wheels locked and I didn't make the turn. It's the biggest mistake of my career, in the biggest race of my career."
Despite his lapse and the chance at his first Indy Lights victory eluding him, Krohn said he had a wonderful time in his first visit to this city for the Baltimore Grand Prix.
"Amazing event, amazing crowd, amazing track," Krohn said. "It was such an enjoyable weekend. It's tough to end it this way."
Guerrieri said that his mistake came when he turned too close to Turn 3, a hairpin turn. It marked the fourth time in 12 races this season that Guerrieri had failed to finish.When he realized he was finished for the day, Guerrieri sat in his cockpit, hands on his helmet, trying to extricate himself from his harness
Asked what he was thinking while he was sitting in his car, Guerrieri said, "Why I didn't become a tennis player."
Echoing the statement made by countryman Roberto De Vicenzo, who said "What a stupid I am " when he lost the 1968 Masters for signing an incorrect scorecard, Guerrieri called it "the stupidest mistake of my career."
Sitting with Guerrieri in the trailer, teammate Connor Daly tried to cheer up his friend. Daly had crashed earlier and had watched as Guerrieri's car spun after hitting the wall.
"I thought the race was over and you were doing figure 8s," Daly joked.
Baltimore Sun reporter Kevin Cowherd contributed to this article.