Matusz allowed eight runs and nine hits in 3 1/3 innings, with one walk, two strikeouts and two home runs. He threw 70 pitches, the last resulting in Jon Jay's three-run homer.
Alfredo Simon replaced Matusz, who has surrendered 14 runs and 18 hits in his last two starts covering eight innings.
Rick Adair and catcher Matt Wieters both made trips to the mound in the fourth - Adair after No. 9 hitter Skip Schumaker's single, and Wieters after Ryan Theriot's RBI single. Jay followed with his shot to left field, and manager Buck Showalter came out of the dugout.
Matusz's fastball hit 90 mph at least once tonight, but he was pretty much in the 86-89 range. The home runs by Lance Berkman and Jay came on 88 mph fastballs. But Matusz was throwing everything.
Jay struck out looking at a slider in the first inning. Colby Rasmus struck out looking at a changeup in the second. Schumaker's single in the fourth came on a slider.
Matusz has allowed 22 earned runs and 29 hits in his last four starts covering 14 2/3 innings. He hasn't topped 5 2/3 in any start this season.
Showalter will face more questions later tonight about Matusz's immediate future with the team.
The Orioles, meanwhile, have one quality start in their last 13 games. And they're in serious danger of being swept by the Cardinals before heading to Atlanta to begin a 10-game road trip.
Instant update: Showalter might also face more questions about keeping Nolan Reimold in the lineup. Reimold, starting for the first time since June 19, hit a 406-foot, three-run homer off Jaime Garcia in the bottom of the fourth. It's Reimold's first homer since May 26 against Kansas City.
Cardinals 8, Orioles 3.
Update II: Mark Reynolds hit his 15th home run, the most of any third baseman, in the sixth inning after Matt Wieters walked with one out. Cardinals 8, Orioles 5.
Jaime Garcia was removed from the game after the home run. This is only the second time in 17 starts that he's allowed more than three earned runs.