A 14-year-old boy who was standing on a Brooklyn sidewalk was hospitalized last night after a Porsche SUV driver slammed into him at "40 mph," according to a witness. The driver, who was apparently trying to pass another car, was arrested.

The incident occurred just after 6 p.m. in Greenpoint. The driver of a 2011 Porsche Cayenne was traveling west on Greenpoint Avenue and trying to pass another vehicle when, a police spokesman says, he crossed the double yellow line into oncoming traffic. The driver ended up sideswiping the other car and barreled into the teen, who was standing outside 172 Greenpoint Avenue.

"I thought it was a bomb or something. He flew 10 feet in the air," an employee at a check cashing business next door said to the Post.

A witness told the Daily News that the Porsche driver seemed to have "road rage": "There was a white Honda Accord coming out of a parking space on the street and the white Porsche was stuck behind him... And then the driver of the Porsche hit the gas and lost control and he drove onto the sidewalk. When the Porsche hit the kid, the kid went flying 10 feet like a little rag doll. His body hit the sidewalk so hard."

The teen was taken to an area hospital and is in stable condition.

The SUV driver, Guo Lu, 39, of Brooklyn, was arrested for reckless endangerment. He was also cited for moving from a lane unsafely.