PHILADELPHIA -- John Mayberry Jr. finished off his first Opening Day with a shaving cream pie in his face.
Welcome to the big leagues, rookie.
"It's all I can ask for for my first Opening Day," said Mayberry, son of former major leaguer John Mayberry, a two-time All-Star in the 1970s. "My parents were here. It's a special day for us."
Trailing 4-2 to start the ninth, the Phillies got going when Jimmy Rollins and Ryan Howard started with singles off Lyon (0-1). After Raul Ibanez popped up, Rollins stole third and Ben Francisco lined an RBI single. Carlos Ruiz followed with a single and Wilson Valdez hit a tying single that kept the bases loaded with one out.
Mayberry then sent a shot over drawn-in center fielder Michael Bourn, kicking off a celebration after he touched first base. He then got that pie in his face during a postgame interview.
"I saw momentum continue to build and nobody wanted to make the last out," said Mayberry, a former first-round pick by the Texas Rangers who had 69 career at-bats entering this season.
Danys Baez (1-0) earned the win with a scoreless inning in relief.
Myers, the Phillies' opening day starter from 2007-09, allowed two runs -- one earned -- and three hits in seven innings.
Sporting a long, bushy goatee, Myers threw just 85 pitches, partly because he didn't have any strikeouts. The Phillies didn't even swing and miss against him until the seventh, but they didn't hit the ball too hard despite making plenty of contact -- until the ninth.
"I didn't pay attention to the pitch count," Myers said. "I could have gone to 120 if I had to."
Halladay, the reigning NL Cy Young Award winner, allowed one run and five hits, striking out six in six innings. Myers had two of those hits.
"I didn't get as deep as I would've liked," Halladay said.
Myers had something to do with that. He picked up where he left off last year. A former first-round pick by the Phillies, Myers was 14-8 with a 3.14 ERA in his first season with the Astros and pitched at least six innings in 32 of his 33 starts.
The four-time NL East champion Phillies became instant favorites to win their second World Series title in four years after signing Cliff Lee in December. But injuries took a toll in the spring and they entered the season without Utley, their five-time All-Star second baseman, and closer Brad Lidge.
They're going to need more production from a lineup that features two former MVPs and five former All-Stars to avoid having dramatic finishes.
"When you look at our pitching, we're going to be in a lot of games," manager Charlie Manuel said. "If we can score some runs, we're gonna win a lot of them."
Valdez, filling in for Utley, and Francisco, taking Werth's place for now, delivered key hits in the ninth.
The Astros broke through against Halladay in the sixth. Angel Sanchez led off with an infield single on a slow grounder that rolled under second baseman Valdez's glove. Hunter Pence followed with a double off the fence in right center. Sanchez scored on Bill Hall's one-out groundout to give Houston a 1-0 lead.
Halladay departed after that inning and the Astros tacked on three more runs in the seventh. Brett Wallace singled off reliever J.C. Romero, and reliever David Herndon allowed a single to Humberto Quintero. After Myers sacrificed, Bourn hit a triple to right-center for a 3-0 lead. Sanchez followed with a sacrifice fly to make it 4-0.
The Phillies cut the deficit in half in the bottom half. Placido Polanco walked, Rollins singled and they advanced on Quintero's passed ball. A sacrifice fly by Howard and RBI groundout by Ibanez got the Phillies within 4-2.
Halladay struck out five of the first eight batters he faced and didn't allow a runner until Myers punched a single to center in the third. Myers' hit surprised even his teammates, who chuckled in the dugout.
Myers got another one his next time up, too. With two outs in the fifth, Quintero reached second when right fielder Francisco dropped his liner for an error. Myers then lined a single to right, but Quintero held up. Halladay escaped the jam by retiring Bourn on a fly to deep right.
Halladay won 21 games in his first season with the Phillies, including a perfect game. He then tossed a no-hitter in his first career postseason start.
Manuel got the first standing ovation of the afternoon when he argued a call at first base in the third. After Valdez lined a one-out double to left, Halladay hit a grounder up the middle. Shortstop Sanchez ranged far to his left, knocked it down and his throw to first appeared late. But first-base umpire Bob Davidson called Halladay out, prompting Manuel to jog out and express his thoughts.
A day that began with big snow flurries falling followed by a steady drizzle that canceled batting practice ended up being pretty decent. It was only 41 degrees, but the skies were clear by the time Halladay threw the first pitch at 1:10.
For the first time in three years, the pregame festivities didn't include a banner-raising because the Phillies fell two wins short of three-peating as NL champions.
Led by the Phanatic, their furry green mascot, players marched down the street outside the ballpark and entered the field from Ashburn Alley behind the stands in left-center field. They walked through the crowd, mingling with adoring fans, and onto a red carpet that stretched from the warning track to the infield.
A crowd of 45,237 was the 124th consecutive regular-season sellout at Citizens Bank Park.
The Phillies are 58-69-2 on Opening Day. ... The last time the Phillies opened against Houston was during their 1993 NL championship season. ... Myers was Houston's first opening day starter other than Roy Oswalt, currently on the Phillies, since Wade Miller in 2002.