MIAMI — Stoic as always, Roy Halladay's expression never changed.

Until the end, that is.

Until there was history — a perfect game, the marquee performance of his All-Star career.

The Philadelphia Phillies' ace threw the 20th perfect game in major league history, beating the Florida Marlins, 1-0, last night.

When he got pinch-hitter Ronny Paulino to hit a grounder to third for the 27th out, only then could Halladay bask in his moment — breaking into a big smile and wrapping his arms around catcher Carlos Ruiz before disappearing in a joyous, jumping gray-and-red mob of teammates.

"It's never something that you think is possible," Halladay said. "Really, once I got the two outs, I felt like I had a chance. You're always aware of it. It's not something that you expect."

It was the second perfect game in the majors this month alone, unheralded Dallas Braden doing it for Oakland against Tampa Bay on May 9. It's the first time in the modern era that there were a pair of perfectos in the same season — Colorado's Ubaldo Jimenez threw a no-hitter, too, in April.