ST. LOUIS -- Scott Feldman authored a nice rebound from a shaky Opening Day start.
Feldman, who couldn't make it out of the fifth inning in absorbing a 4-3 loss to Philadelphia on Monday, gave up four hits and a walk while fanning six to square his record at 1-1.
Duvall started Cincinnati's 11-hit attack with a leadoff homer in the second off Carlos Martinez (0-1), then added two singles and a walk. His third hit, a liner to left center, plated Jose Peraza to start a four-run sixth that decided the game.
The Reds (4-2) got plenty of help later in the outburst from the Cardinals (2-4), which mixed in three errors before getting an out in the inning.
That chased Martinez. Reliever Brett Cecil coughed up an RBI double to right on his first pitch to Scott Schebler. Randal Grichuk bobbled the ball for the inning's third miscue, allowing Suarez to score all the way from first for a 6-0 advantage.
Martinez gave up six hits and six runs (five earned) in five-plus innings with a walk and three strikeouts. It was a performance far removed from his Opening Night start on April 2 when he fanned 10 Chicago Cubs in 7 1/3 scoreless innings.
Cincinnati won a series in St. Louis for just the fifth time in its last 40 attempts dating to 2003. The Reds have lost 32 series in that time, splitting three others.
Votto added a solo homer in the ninth for Cincinnati.
NOTES: St. Louis LHP Tyler Lyons (right knee) threw a bullpen session Sunday and said he expects to make his next rehab start Wednesday for Triple-A Memphis. He pitched 3 1/3 scoreless innings Friday night in New Orleans. ... Cincinnati C Devin Mesoraco (hip) caught seven innings on a rehab assignment Saturday night for Double-A Pensacola, belting a two-run homer against Tennessee. Mesoraco had Sunday off and will attempt to catch a full game Monday night. ... Cardinals OF Stephen Piscotty (knee soreness) missed a second straight start.