Paul Pelosi was able to alert cops to the crazed hammer intruder who had broken into his and Speaker of the House Nancy Pelosi's house by speaking in code, sources say.
Mr Pelosi had dialled 911 but couldn't speak to the operator in case it alerted the attacker.
Instead he spoke to the attacker giving enough detail so the officer on the other end of the line could overhear and understand something was wrong.
The quick thinking dispatcher issued a high priority welfare check and officers rushed to the scene.
On arrival at the San Francisco home they saw the incident had escalated with the intruder and Mr Pelosi grappling for a hammer. As officers crossed the room, the attacker allegedly wrestled the weapon off the 82-year-old victim and struck him over the head.
The suspect, who has been named as 42-year-old David Depape, was tackled by police and arrested.
Mr Pelosi was taken to hospital with head injuries and needed surgery but tahnkfully is expected to make a full recovery.
San Francisco Police Chief William Scott praised the quick-thinking dispatcher. He said: “When you have an experienced dispatcher with good instincts, they learn how to read between the lines."
A source told CNN Pelosi was talking in code, giving enough information so the call operator new something was badly wrong.
Scott continued: “She knew something more was going on, just in her heart and her intuition, just with her experience.
“And that calls for a higher priority than this type of call normally receives. This was a well-being check. And she just knew there was more to it. So she alerted our officers, she went that extra step … and that led to a quicker response.”
The struggle was captured on police body cameras as officers entered the residence.
The intruder, 42-year-old David Depape, reportedly confronted the speaker's husband as he stormed into the couple's home and shouted "where is Nancy, where is Nancy?".
“Early this morning, an assailant broke into the Pelosi residence in San Francisco and violently assaulted Mr Pelosi,” spokesman Drew Hammill said in a statement.
“The assailant is in custody and the motive for the attack is under investigation" it continued.
Nancy Pelosi, who is second in line to the U.S. presidency, was not at home at the time of the early morning assault.
“The Speaker and her family are grateful to the first responders and medical professionals involved, and request privacy at this time,” the statement concluded.
Mr Pelosi owns a real estate and venture capital firm.
It is not the first time Pelosi’s home has been targeted. In January of last year, their Pacific Heights home was vandalised overnight with a pig's head surrounded in a pool of red paint, as well as a spray-painted message.
Also, a North Carolina man, Cleveland Meredith, was sentenced last December to 28 months in prison after pleading guilty to threatening to shoot Pelosi.
Meredith, 53, had travelled to Washington, D.C., on January 6, 2021, planning to attend rallies on that day, but didn’t arrive until the evening, when the pro-Trump riot at the U.S. Capitol had been tamped down.
Another man, Steven Martis, 77, of Arizona, was sentenced in February to 21 months behind bars for threatening to kill Pelosi in messages to her Washington DC office.
The attack on Mr Pelosi comes as the US Capitol Police record a drastic rise in threat cases - a 144 per cent increase from 2017 to 2021, according to the department.