A fearless firefighter raced inside a burning Brooklyn building Monday and saved a 2-year-old boy from the furious flames.

Lt. Victor Milukas said there was “zero visibility” and “high heat” and that he only had a general idea where little Justin Pierre might be as he searched the second floor of a Marine Park house.

“I just kind of took a chance and figured, ‘I’m gonna have to check this room,’” he said.

Milukas’ hunch proved right and he found the unconscious toddler by feeling around beneath a pile of clothing.

“To me it was a blur,” Milukas said afterward outside Ladder Co. 159 firehouse on the Flatlands/Marine Park border. “Luckily I was able to find the baby.”

Justin was at Staten Island University and in a medically induced coma, but his dad says he expects his boy will pull through.

“He’s critical, but the prognosis is much better,” said Jean Pierre, who is a registered nurse. “He only has a blister and smoke inhalation.”

Justin’s relieved dad said he was told the fire started in his son’s bedroom and was sparked by an electrical malfunction.

The drama on Avenue P began a little after 1 a.m. Monday.

Pierre, a married father of four, said he was at work at Maimonides Medical Center and that his oldest daughter first smelled the smoke and sounded the alarm. He said in their rush to escape the building, Justin got overlooked.

“When my wife went back to get him the first time, the fire completely engulfed the place,” Pierre said.

Milukas said they got the call at 1:13 a.m. and encountered a “very chaotic scene” and a house engulfed by smoke when they arrived.

“People (were) yelling that the baby was still inside,” he said. “There was a neighbor who had climbed up on a front porch roof and was attempting to enter the building by removing the air conditioner.”

Milukas said they donned their masks and headed into building and the inferno.

“We made our way to the top of the stairs and we had zero visibility, high heat,” he said. “We couldn’t tell where the fire was.”

Milukas said he first checked the rooms “where everyone said the baby was in.”

“As I was going down the hallway, I felt a lot of heat on my right,” he said. “My inside team at that point was searching the rear bedrooms. I made a quick search of the front bedroom and realized that this was a master bedroom and I couldn’t find the baby in there.”

Quickly, Milukas retraced his steps to the spot in the hallway where he felt the high heat. He burst inside a bedroom and found a mattress ablaze.

Milukas said he swept his hand across the mattress to see if the toddler was on it. “It was in flames,” he said.

“I quickly found the wall again and got to a corner and there was a pile of clothes on the floor,” he said. “As I was searching the floor, I came across the (seemingly) lifeless infant.”

Milukas said scooping the boy up into his arms was “surreal.”

“I have kids of my own,” he said. “Your adrenaline goes up even more. Every life is precious but you know, for a child you go above and beyond.”

Milukas said he quickly brought the child outside to another firefighter to immediately begin CPR.

“At that point, I knew the baby was in good hands,” the hero firefighter said. “Got my helmet and went back into the fire building and operated with all the other members to complete the searches and extinguish the fires.”

Milukas, an 18-year veteran of the fire department who lives in East Rockaway, is no stranger to heroics.

Back in 2007, when Milukas was assigned to Ladder 142 in Queens, he saved a 45-year-old man from a burning building in Richmond Hill.