The Reds remained stuck with the worst record in the majors at 31-51, on pace to lose 100 games for the first time since 1982. The Reds became the second team to change managers Sunday after Seattle's Mike Hargrove resigned earlier in the day.
Advance scout Pete Mackanin, who managed the Reds' Triple-A team in Nashville from 1990-92, was chosen interim manager. He was the Pirates' interim manager for the final 26 games of the 2005 season after Lloyd McClendon was fired.
Owner Bob Castellini and general manager Wayne Krivsky declined comment until a news conference on Monday, a day off before the start of a home series against the San Francisco Giants.
Ludwick's solo homer landed above the batter's eye, and along with his three-run shot, offset another noteworthy homer by Ken Griffey Jr.
"I've hit balls that hard before, but in the minor leagues they don't measure them," Ludwick said of his solo homer. "Here they happen to measure them."
This one came in at 473 feet, tied for the ninth-longest in Great American Ball Park's five seasons. Ludwick was rounding the bases with his head down when it landed in a riverboat-themed party area above the batter's eye.
"You knew it was gone, but you weren't sure how far," left-hander Mike Maroth said. "It got up there on the balcony of the ship. That's pretty impressive."
The Cardinals overcame a disappointing start by Maroth, who gave up Griffey's 585th career homer and left the game after failing to get an out in the fourth inning.
Instead, the latest addition to the bullpen came through again.
Reliever Troy Percival (2-0) got his second victory of the series, a triumphant return for the former closer. The 37-year-old reliever was out of baseball for two years because of a bad elbow, but made a comeback at the urging of several friends on the team.
Throwing a 90 mph fastball that has surprised everyone, Percival pitched out of a threat in the fourth to get the victory.
In another dose of discouragement for the major leagues' worst team, Reds rookie Homer Bailey got hit hard for the second straight start. The defining moment came in the third, when Ludwick -- playing while Juan Encarnacion got a day of rest -- hit a knee-high fastball into the party center.
"It was a beautiful thing to see," manager Tony La Russa said. "He was clutch. Plus, he hit another one. The way that game was going, we needed every one of them."
Ludwick added a tiebreaking, three-run homer in the fourth off Ricky Stone, the second multihomer game of his up-and-down career. The 28-year-old outfielder has played parts of seasons with Texas and Cleveland, spending most of his career bouncing around the minors.
His family is part of Cardinals lore. His brother, Eric, pitched for St. Louis and was one of three players traded to Oakland for Mark McGwire on July 31, 1997.
Ludwick is still trying to find his way.
"I've been real inconsistent here," said Ludwick, who was called up May 6. "The good games have happened to be at good moments, when it's mattered."
Chris Duncan added a two-run homer for the Cardinals, who took two of three in the series.
Griffey's three-run homer left him one behind Frank Robinson for sixth on the career list and was a prelude to his matchup in the next series against San Francisco's Barry Bonds.
Neither starter made it through the fourth inning, a particular disappointment for two teams near the bottom of the league in pitching.
The Cardinals got Maroth from Detroit in a June 22 trade to steady their depleted rotation. The left-hander gave up five runs in his second start for St. Louis, raising the rotation's earned run average to 5.42, worst in the NL.
The hard-throwing Bailey (2-2) got hit hard for the second consecutive start, raising questions about his readiness for the big leagues. The 21-year-old pitcher has given up 13 hits, eight walks and 13 runs in his last two starts, covering only 5 1/3 innings.
Bailey blamed it on a flaw in his delivery that he detected while watching video afterward.
"I knew something was wrong, but I couldn't figure out what it was," Bailey said. "It's a small, mechanical thing. We have an off day tomorrow, which gives me an extra day to remember how bad today was."
- Ludwick's solo homer was the seventh to clear the front of the batter's eye in center.
- Ludwick also homered twice on Aug. 12, 2003, at Minnesota for Cleveland.
- Reds SS Alex Gonzalez committed his team-high 14th error, twice as many as he had last season for Boston.
- Bonds is 5-for-26 (.192) career at Great American with only two homers. Bonds hit No. 730 last Sept. 4 at Great American, and Griffey dislocated a toe on his right foot while trying to climb the padded wall to catch it.