The jogger, Sam Dempster said as he collapsed, Hoffman, who lives nearby in Kensington came to his rescue by dialing 999 and tending the stricken runner, Sun reported.
Hoffman, 74, known for his stirring performances in "The Graduate", "Midnight Cowboy" and "Rain Man" had seen the jogger falling and stood by Dempster's side for 15 minutes till cardiopulmonary resuscitation was performed on him and his heart started beating again.
A wonder struck Dempster later wrote a thank you on his Blog to Hoffman.
"A big thank you... To my new favourite celebrity Dustin Hoffman who called 999 and waited by my side until paramedics arrived," Dempster said.
Paramedics told The Sun newspaper that Hoffman had watched fascinated as they re-started Dempster's heart with electric shocks.
And later Hoffman walked up to the medics saying, "Great job guys".
