PHILADELPHIA—Roy Halladay spent his whole career waiting for this start, wondering what it would be like to pitch in the playoffs.It was better than he — or anyone else — could have predicted.Halladay threw the second no-hitter in postseason history, leading the Philadelphia Phillies over the Cincinnati Reds 4-0 in Game 1 of the NL Division Series on Wednesday.Don Larsen is the only other pitcher to throw a postseason no-hitter. He tossed a perfect game for the New York Yankees in the 1956 World Series against Brooklyn. The 54th anniversary of Larsen’s gem is this Friday.Halladay took the Year of the Pitcher into October. The excitement spread beyond Citizens Bank Park — the last two outs were shown on the video board at Target Field, where the Twins were preparing to play the Yankees, and Minnesota fans cheered.The All-Star right-hander, who threw a perfect game at Florida on May 29, dominated the Reds with a sharp fastball and a devastating slow curve in his first playoff start.The overmatched Reds never came close to a hit. Halladay allowed only one runner, walking Jay Bruce on a full count with two outs in the fifth, and struck out eight.Halladay threw 104 pitches, 79 for strikes. “It’s no fun out there,” Reds slugger Joey Votto said. “It’s like trying to hit nothing. He’s an ace among aces.” Halladay spent 12 seasons with Toronto, far from the postseason. A trade last December brought him to the defending two-time NL champions, and gave him this chance.With a sellout crowd standing in the ninth and chanting “Let’s Go, Doc!” Halladay got a loud ovation when he jogged to the mound to start the inning.Ramon Hernandez popped out to second baseman Chase Utley for the first out. Pinch-hitter Miguel Cairo then fouled out to third baseman Wilson Valdez.Halladay then retired Brandon Phillips on a tapper in front of the plate to end it. Catcher Carlos Ruiz pounced on the ball, getting down on his knee as the ball rolled near Phillips’ bat, and made a strong throw for the final out.