Bush sat between first lady Laura Bush and Secretary of State Condoleezza Rice as they and several guests settled into a VIP box during the first inning.
Unlike Bush's previous visits to RFK Stadium, there was no red, white and blue bunting in front of the box to identify the important visitor, and there were no obvious signs of extra security before the game.
There was no advance word that Bush would be attending and reporters accompanying him were not told where he was going until the presidential motorcade neared the ballpark.
The president and his party left in the middle of the seventh
inning with San Diego leading 5-1 and went back to the White House.
The Padres won 5-2.
Among others attending the game with the president were his
brother, Marvin, Attorney General Alberto R. Gonzales and Chief of
Staff Josh Bolten.
Bush, a former part-owner of the Texas Rangers, has attended three Nationals games at RFK since Major League Baseball returned to Washington last year. He threw out the ceremonial first pitch amid much fanfare at the 2005 home opener, the stadium's first game since 1971. He and Rice also attended a game in June. The Nationals won both games.
Vice President Cheney threw out the first pitch at this year's home opener and was greeted with what seemed to be more boos than cheers as he walked on the field.