John Kerry (search) made a surprise appearance at the Yankees-Red Sox baseball game Sunday night to throw out the opening pitch to a soldier home from Iraq, making an early arrival in the city where Democratic delegates were gathering to nominate him for president.

Sen. Kerry arranged for his flight between the battleground states of Ohio and Florida to be diverted to his hometown of Boston, where he had not been scheduled to make his grand entrance to the convention city until Wednesday afternoon. He said he planned the trip in secret about a week ago.

"The idea of missing a Yankees-Red Sox series right before a convention week was not acceptable, so we changed the policy," Kerry told reporters on the plane.

Kerry was to throw out the first pitch to Will Pumyea, 23, a military police officer in the Massachusetts National Guard, from North Chelmsford, Mass., who had just returned from Iraq and who had previously served in Afghanistan.

After throwing the pitch, Kerry was to sit with his wife, his daughters, former Sen. John Glenn (search) of Ohio, the owners of the Red Sox and Pumyea at the game at Fenway Park (search).

Fans attending the game Sunday night did not have to go through metal detectors, which is the normal procedure for anyone attending an event with the Democratic presidential candidate. At Fenway Park, supporters distributed signs reading, "Sox Fans for Kerry."

The game was the third in the Boston homestand between the two fierce rivals -- who are also the teams representing the two convention cities. The Republicans gather in New York in late August. The Yankees won the first game Friday and the Red Sox came back with a dramatic two-run homer in the bottom of the ninth inning to win a fight-marred game Saturday.

Kerry planned to fly on to Florida on Sunday night after the game and resume his schedule.