Born in St. Louis, Howard is a .383 career hitter there with seven homers and 28 RBIs in 60 at-bats.
"Here is where it all kind of began," he said. "I just play well. I'm not going to knock it, I'm going to take it."
Ankiel crashed headfirst into the outfield fence after chasing down a line drive to the gap in the eighth inning. He flashed a thumbs-up sign as he was carted off the field strapped to a gurney and wearing a neck brace.
The outfielder was taken to a hospital for X-rays and a CT scan of his head, neck and back, which were all negative and showed no fractures, team spokesman Brian Bartow said. Ankiel remained hospitalized overnight for observation and the team said he was day to day.
Cardinals physician Dr. George Paletta told manager Tony La Russa that Ankiel showed signs of whiplash and puffiness in his face.
Paletta told the team that Ankiel never lost consciousness on the field.
"It's a scary thing to see, there's no doubt about it," Cardinals general manager John Mozeliak said.
Joe Blanton (1-2) allowed a run in six innings for his first win since Sept. 26 while giving Philadelphia's rotation only its fifth win this year. Jayson Werth added a two-run shot for the Phillies, who chased Kyle Lohse (3-1) with one out in the fifth for his shortest outing since Aug. 12, 2008.
Lohse struggled after getting hit by a pitch in his left elbow in the third. The right-hander said that arm was numb for much of the remainder of his outing.
"I was pretty sore, but that's not an excuse," Lohse said. "I left a couple of balls right where the game plan was to not put those pitches."
Joe Thurston had three hits and an RBI for the Cardinals, who have lost two straight at home after winning nine in a row.
Howard hit a 1-1 pitch from Lohse well over the right-field wall, an estimated 428 feet, for his fifth homer in the fifth inning to put the Phillies ahead 6-1. It was his second slam of the season after connecting off the Nationals' Shairon Martis last Monday in Philadelphia, and it came only three pitches after Lohse got a visit from trainer Barry Weinberg.
Howard attended Missouri State University. He and the Cardinals' Albert Pujols, who was 0-for-3 with a walk, each have two grand slams to tie for the major league lead.
Tying Schmidt was just as impressive to the Phillies' slugger.
"That's a pretty good feeling when you're doing something like that," Howard said. "Anytime you can be mentioned in the same sentence with a guy like Mike Schmidt, it's always a great feeling and an honor."
The Phillies have hit four grand slams overall and are an NL-best 14-for-27 with the bases loaded, while leading the majors with 11 bases-loaded walks and 46 RBIs.
Lohse pitched for the Phillies in the 2007 playoffs, then signed a free-agent deal with the Cardinals during spring training in 2008.
Blanton, who entered with an 8.41 ERA, allowed four hits in six innings and worked out of a couple of jams. The Cardinals left two on twice and then left the bases loaded in the sixth.
Ankiel ran full speed to track down Pedro Feliz's drive in the eighth and couldn't stop himself from slamming into the padded outfield wall.
The converted pitcher took 2 1/2 off-balance steps after making the catch and had the presence of mind to take the ball out of his glove before attempting to brace himself with his left arm. Still, his head appeared to absorb most of the blow when he smacked into the fence.
Ankiel stayed flat on his back for several minutes as teammates gathered around him, and the game was delayed about 15 minutes as a hush fell over Busch Stadium. He was placed in a neck brace and strapped to a gurney before being carted off the field accompanied by Paletta and Weinberg.
The Phillies have come from behind in 11 of their 13 victories. ... Lohse entered 2-1 with a 2.20 ERA against the Phillies in five career starts. He's allowed 15 runs this season, eight of them in the fifth. ... The Phillies have 24 homers in 16 games at new Busch.
Information from The Associated Press contributed to this report.