The sharpshooting policewoman who halted an attempted robbery at a Brooklyn beauty salon last weekend was promoted Tuesday to the rank of detective during a ceremony at City Hall.

Mayor Michael Bloomberg administered the oath of office and gave a gold shield to Police Officer Feris "Jonesey" Jones, 50.

Jones, a 20-year veteran of the department, was off-duty and getting her hair done at Sabine's Hallway Beauty Salon in Clinton Hill on Saturday night when authorities say Winston Cox, 19, burst through the door with a gun.

Cox forced Jones and three others into the bathroom.

Investigators say Jones identified herself as an officer and told Cox to drop his weapon.

When Cox opened fire and barely missed Jones, the officer fired back and shot the gun out of Cox's hand.

Another shot broke the lock on the door, but police say Cox escaped by breaking the glass and crawling out.

Jones then called 911 and gave a precise description of Cox.

Police Commissioner Ray Kelly said that Jones showed stunning marksmanship.

"It's one thing to do that, and do it well, safely away from the action. It's quite another after someone 12 feet away just tried to kill you. To describe Officer Jones as cool under fire would be a gross understatement," Kelly said.

"What makes this story all the more impressive is that during her 20 years on the force, officer Jones has never had to fire her gun at an assailant," said the mayor.

Jones told reporters at her promotion ceremony that she is "always armed" and she said, "I was using my training." Her sole goal during that incident was that she and all the other women in the shop "had to get out of there in one piece."

Asked how the other women reacted, Jones said, "I got a lot of hugs."

At the salon Tuesday, workers were cleaning up all the glass and debris. Many were still shaken up and reluctant to talk about what happened.

"We're just happy that it's working out in some form or fashion," said one salon worker.

Cox was subsequently arrested early Monday morning at a Bedford-Stuyvesant hotel and he is being charged with attempted murder and robbery.

Police say they recovered the gun used in the robbery and two customers' wallets at the apartment of Cox's mother.