Book excerpt: Ingemar Johansson's right hand--dubbed "The Hammer of Thor"--was the most fearsome in boxing, and Johansson's three fights with Floyd Patterson rank among the sport's classic rivalries. Yet most fans know little about the Swedish playboy who won the world heavyweight championship with a shocking third round knockout of Patterson and held it for six days short of a year (1959-1960). During his reign, the raffish "Ingo" hit fashionable nightspots on two continents, romanced Elizabeth Taylor, and refused to kowtow to the mobsters who controlled boxing. This first-ever biography of Johansson chronicles his fistic triumphs as a Goteborg teen prodigy, his humiliating disqualification for "cowardice" at the 1952 Olympics, his storybook romances with Birgit Lundgren and Edna Alsterlund and his post-career life and tragic early dementia.