A little more than seven hours after he put on his Buffalo Bisons jersey, Ike Davis stood on first base at Citi Field in a New York Mets uniform holding the ball from his first big league hit. What a day. Called from Triple-A at around noon to help the slumping Mets, the top prospect had two hits and an RBI in his debut, a 6-1 victory over the Chicago Cubs on Monday night.