Suffolk District Attorney Kevin Hayden praised the “extraordinarily brave intervention” of a neighbor who heard the woman’s screams and rushed to help.

Amos Sykes was arraigned in Boston Municipal Court for the alleged sexual attack on a woman, on a South End street, on Saturday. Pat Greenhouse / The Boston Globe

A Quincy man was ordered held without bail Monday as he faces charges for allegedly assaulting a woman and attempting to remove her clothes during an attack in the South End Saturday night. 

Amos Sykes, 35, appeared in Boston Municipal Court and was charged with assault with intent to rape, strangulation or suffocation with serious bodily injury, and assault and battery with serious bodily injury, among other offenses, according to The Boston Globe. It was not immediately clear whether he had an attorney who could speak to the charges.

A judge ordered Sykes held without bail pending a dangerousness hearing Wednesday, the Suffolk County District Attorney’s Office said. A not guilty plea was entered on his behalf.

Boston police previously said the call came in at about 9:39 p.m. Saturday for an assault and battery in progress in the area of Appleton and West Canton streets.

The woman had been walking on Columbus Avenue when Sykes allegedly grabbed her from behind, forced her onto the ground, punched her in the head, and attempted to take off her clothing, police said in a press release. 

Officers arrived at the scene and saw a witness fighting with Sykes in an attempt to defend the woman, police said. Boston EMS took the woman to a local hospital with nonlife-threatening injuries.

In a statement Monday, Suffolk District Attorney Kevin Hayden said the “nightmarish attack … would likely have resulted in an even worse outcome if not for the extraordinarily brave intervention of a Good Samaritan.”

Hayden added: “In cases like this the victim’s injuries often transcend the physical. Our office has advocates specially trained to treat this type of trauma, and they will be by this victim’s side throughout the court process and after. I thank Boston Police for their quick response and arrest and I am especially grateful for this Good Samaritan’s courageous action.”

The Good Samaritan, Sam Holder, told WHDH that he and his father were watching a football game when they heard the woman screaming for help. 

“We heard a shriek … so I came outside,” Holder told the news outlet. He recalled seeing the woman laying on the ground with Sykes allegedly on top of her.

“I just jumped in, I had no other choice,” he told WHDH. “She was screaming and bloody, with her pants down around her ankles.”

In a separate interview with WCVB, Holder shied away from praise. 

“I’m not a hero. I’m not a hero at all,” he told WCVB. “I just did what any man should do.”