A niggling little golf rule unheard of by most Americans infused the PGA Tour with more excitement last week than at any other time this season, tour officials, fans, and players confirmed Sunday. 'Dustin Johnson illegally grounding his club because of an inability to determine whether or not he was in a sand trap or waste area was exactly the shot in the arm the PGA Tour needed,' Commissioner Tim Finchem told a throng of excited reporters, referring to the minor rules violation that eliminated the 26-year-old golfer from a playoff to determine the PGA champion and galvanized fans worldwide. 'Rule 13-4 is just awesome. Only golf can bring that kind of excitement.' Finchem said he hasn't been this energized about the game since Phil Mickelson's wedge controversy back in January. 