There have been 20 perfect games in Major League history, but only five Cy Young Award winners have hurled them: Halladay, Randy Johnson, David Cone, Jim "Catfish" Hunter and Sandy Koufax.
The 2010 season is the first time since 1880 that two perfect games have been hurled in the same year. The Athletics' Dallas Braden also threw one on Mother's Day on May 9.
Halladay is the sixth pitcher in Major League history to throw a perfect game with a 1-0 victory. The last one to do it was the Reds' Tom Browning in 1988.
Halladay's 11 strikeouts were tied for the third-most in perfect-game history.
The Phillies are the fifth team in Major League history -- and the only one in the National League -- with two perfect games, joining the Indians, White Sox, Yankees and A's.
According to the Elias Sports Bureau, this is the third season in Major League history in which three no-hitters came before the start of June.