Halladay earned his 21st win with his fourth shutout and ninth complete game -- all highs in the majors this season -- and Jayson Werth drove in four runs, leading the Phillies to a 8-0 victory over the Washington Nationals on Monday night, wrapping up the division with five games left.
Halladay (21-10) heads to the playoffs for the first time in his 13th major league season, having played his entire career with the Toronto Blue Jays before being traded to Philadelphia last winter.
Normally stoic on the mound, the former Cy Young winner punched his glove with his pitching hand after striking out a swinging Danny Espinosa for the final out.
Halladay's years without a postseason trip were tied for fourth-most among active players; the highest total on that list belongs to Mike Sweeney, a bench player whose drought ends in his 16th season.
"It was fun, but it's only going to get funner," Halladay said. "Honestly, it didn't matter who finished it as long as we got it done."
The Phillies have the best record in the NL. It's still uncertain who they will face at home next week in Game 1 of the division series.
Halladay gave up a single to Wilson Ramos in the third, and another to Adam Dunn in the eighth. That was it.
The right-hander didn't walk a batter and struck out six, including one to end each of the first three innings. He faced the minimum 21 batters through seven innings.
The Phillies went ahead 1-0 on the first of Werth's three hits in the game. It was his 26th homer, a drive to left field off John Lannan (8-8) in the second inning.
Because of Halladay's dominance, that would have been enough to win Monday. But Werth made it 3-0 in the sixth, delivering a two-out, two-run double to right-center after Lannan walked Placido Polanco and hit Chase Utley with a pitch. Carlos Ruiz's RBI double later in the inning, off Craig Stammen, drove in Werth and stretched the lead to 4-0.
Lannan, in his final start of the season for the last-place Nationals, gave up four runs and seven hits in 5w innings.
The Phillies improved to 46-17 since July 21, when they trailed Atlanta by seven games. Eight days later, they traded for Roy Oswalt, adding him to Halladay and 2008 World Series MVP Cole Hamels for as fearsome a threesome of starting pitchers in the majors.
Philadelphia is 20-5 in September, its most wins in the season's final month since compiling 22 in 1983.