The result was a lopsided victory that encapsulated one team's struggles and another's bright future.
"Anytime you face Doc, it's something special," said Harvey, who admitted to feeling a bit star-struck. "We put up runs against him, and fortunately I was able to put up zeros for us."
Halladay's trouble began when Marlon Byrd, who authored Sunday's walk-off victory against the Marlins, punched a one-out double into center field in the second inning. Halladay plunked the next batter, Lucas Duda, bringing the NL's RBI leader to the plate.
Once again, John Buck converted, crushing a Halladay cutter to the opposite field for a three-run homer.
"It feels like I'm doing what I'm capable of doing," said Buck, whose 12 RBIs are the most by any player in franchise history over the first seven games of a season. "I'm not trying too hard to do too much. I'm just letting it come to me, and the results have been good."
The Mets plated another run off Halladay on Duda's single in the third inning, then knocked the two-time Cy Young Award winner out of the game with three consecutive hits to open the fifth.
The Mets were not completely done with their rout of Phillies pitching, breaking the game open on Ruben Tejada's two-run single off reliever Chad Durbin. That officially closed the book on Halladay, who allowed seven runs on six hits and three walks. He recorded a dozen outs.
"That's not Doc," said Terry Collins, who had never previously beaten Halladay in two-plus years as manager of the Mets. "I don't want to face him all that much, but if you're going to get him, you'd better get him when things aren't right."
No such trouble awaited Harvey, who struck out nine batters in his second start of the season. The Phillies scored their only run off him when Jimmy Rollins doubled to open the fourth inning, moved to third on Chase Utley's single and scored on Ryan Howard's sacrifice fly. Otherwise, Harvey was brilliant, allowing three hits and two walks.
He lowered his career ERA to 2.33 in 12 starts, striking out nearly 11 batters per nine innings.
"He's a top-of-the-rotation guy," said Phillies manager Charlie Manuel.
Though Harvey did allow his first run of the season, his second outing was in some ways more impressive than the first. Lacking the same type of fastball command that defined his season debut, Harvey relied more heavily on his offspeed pitches -- his second-, third- and fourth-best offerings. But the results were nearly identical. Several Phillies hitters looked overmatched vs. Harvey, the same way the Mets have against Halladay for a decade.
Not since the days of Mike Piazza and Benny Agbayani had the Mets beaten Halladay, who lorded over them with an 8-0 record and 2.12 ERA from 2002-12. Halladay walked a total of six batters in his nine most recent starts against the Mets, allowing a total of 16 runs.
So it was almost jarring to see him continually falling behind hitters Tuesday, walking three and giving up seven runs -- the equivalent of half a decade's worth of offense. His struggles were even more pronounced because they came on the same Citizens Bank Park mound that Harvey dominated, reaching 98 mph with his fastball.
Mets hitters cautioned afterward that it will not always be like this. At age 35, even with eroding abilities, Halladay is still respected by the opposition.
"People can say he's struggling or whatever you want, but he's still Roy Halladay," Buck said. "He still throws good."
It's just that on this night, on this mound, Harvey threw better. And it probably won't be the last time that happens.