Dustin Hoffman comes to aid of stricken London jogger Actor/producer Dustin Hoffman arrives at the premiere of HBO's "Luck" on Jan. 25, 2012, in Los Angeles. Credit: Kevin Winter (CBS/AP) LONDON - A man who had a cardiac arrest while jogging in London's Hyde Park says his life was saved with help from a famous passer-by - Dustin Hoffman. Sam Dempster said Tuesday that the actor waited with him after he collapsed on April 27 until paramedics arrived. On his recovery blog, 27-year-old Dempster thanked medical staff and "my newfound favorite celebrity Dustin Hoffman." Pictures: Dustin Hoffman Read More: Dustin Hoffman To The Rescue Dempster initially credited Hoffman with having summoned an ambulance, but the London Ambulance Service said someone else had made the emergency call. Martin Macarthur, one of the paramedics on the scene, said Hoffman described seeing Dempster collapse and froth at the mouth. It is essential to get a history of what has happened, and he witnessed the jogger go down. He was the main witness and saw him stagger and go down," Macarthur said. He stayed on the scene for the whole duration of the resuscitation which was about 15 minutes. He was very concerned. Macarthur said the 74-year-old actor, who starred in the "Marathon Man" movie, told medics, "Great job, guys" after they resuscitated Dempster with a defibrillator. Representatives of the "Tootsie" and "Rain Man" star, who has a home in London, did not immediately respond to requests for comment. This is not the first time Hoffman has come to the rescue of a sick passer-by. In 2007, Lydia Graham was stung by a bee and had a severe allergic reaction while walking on California's Malibu Beach, outside Hoffman's home. The actor and his wife, Lisa, were on their deck and saw the problem. Lisa fetched an Epi-pen that she uses to ease her own allergy symptoms and the the two went to Graham's aid.