Halladay tossed the second perfect game in Phillies history, twirling a 115-pitch gem to post Philadelphia to a 1-0 win over the Marlins.
The achievement joins winning the 2003 American League Cy Young award and racking up 155 wins over 13 years career as high point for the Phillies ace, who had never before thrown a no-hitter, much less major league baseball's 20th perfect game.
"Early in my (pregame) bullpen, I felt like I was hitting spots more than I have been, and I just carried that over," Halladay told MLB.com, adding, "There's days where things just kind of click and things happen, and it's something you obviously never go out and try and do. But it's a great feeling."
Halladay induced pinch-hitter Ronny Paulino to hit a sharp grounder to third baseman Juan Castro, who speared the ball to his left, spun and threw out the runner to end the game and trigger a celebration on the mound.
Halladay (7-3) finished with 11 strikeouts, eight ground ball outs and eight flyouts.
It was the second perfect game this month -- Oakland's Dallas Braden threw one against Oakland on May 9. The only other perfect game in Phillies history was tossed by Jim Bunning against the New York Mets in 1964.