An elderly woman bravely took the stand Monday to confront the teen on trial for raping her when he broke into her Brooklyn home.

The 83-year-old, who has been unable to walk since the brutal incident, was wheeled into Brooklyn Supreme Court past defendant Asa Robert to recount what she called “the most disgusting thing” that has ever happened to her.

“After he raped and tortured me, he brought me a bottle of water,” the grandmother said of the then-18-year-old Robert. “And he brought me my [medical] alert button.”

Robert suffocated, raped and sodomized the frail, 4-foot-5-inch, 90-pound widow, she testified, recalling how he lifted her by the neck and threw her against the wall.

The widow, whose name is being withheld, recalled how she’d even offered to give Robert a keepsake Hawaiian shirt she’d purchased for her late husband — telling him, “You look very nice,” in a bid to get him to leave without harming her.

But as he walked toward the front door after looting the Brighton Beach home she’d shared with her husband, all of a sudden, he turned, and ordered her to get “back in the bedroom,” where he raped her, ignoring her pleas that he call 911 because “I felt like I was having a heart attack.”

“He was on top of me like a pile of bricks,” she recalled, her voice steady. “It felt like he was trying to crush me to death.

“It took a long time for him to get off,” the octogenarian told jurors. “He continued no matter what I said.”

While she did not directly address Robert — who sat sulking at the defense table and could be heard muttering to his attorney that the witness “is just an old woman” — she seemed to freeze when she was asked to identify him, before swallowing and then describing him as her attacker.

Robert, now 20, sneaked into the home after the woman left the front door open to clean outside — which her son-in-law previously testified she did compulsively. She didn’t realize he was in her house until she lay down in bed and saw the shadow of a man rocking back and forth in the corner of her bedroom.

She said he then tore through her home, “rummaging” through belongings, brandishing a knife and demanding money before raping her.

After he left, she called her son-in-law, who phoned police and paramedics.

She didn’t disclose her rape until nearly a week later, after the pain became “too much to handle” and family members noticed a handprint-shaped bruise on her face.

Robert faces 25 years to life in prison on the top charge of predatory sexual assault if convicted.