Kennedy (1-0) allowed two runs on five hits with one walk.
St. Louis' Adam Wainwright (0-1) went six innings, giving up four runs, three earned, on 11 hits. He struck out six with no walks.
Arizona's Gerardo Parra matched his career best with four hits, three of them doubles. Rookie A.J. Pollock was 3 for 4, including a two-run double, and Martin Prado doubled twice with an RBI and two runs scored for the Diamondbacks.
Matt Holliday had an RBI double and Daniel Descalso a run-scoring single for St. Louis.
The Diamondbacks' seven doubles were more than they had in any game in the last two seasons.
Kennedy, 15-12 last year after going 21-4 in 2011, dominated after giving up consecutive one-out doubles to Matt Carpenter and Holliday to put St. Louis up 1-0 in the first.
David Hernandez threw a perfect eighth and Brad Ziegler did the same in the ninth for the Diamondbacks.
Arizona scored three times off Wainwright in the fourth.
After one-out singles by Miguel Montero and Paul Goldschmidt, Jason Kubel lofted an RBI double to right-center to tie it at 1. Pollock, starting because of injuries to Adam Eaton and Cody Ross, lined a double off the glove of center fielder Jon Jay to bring in two and Arizona led 3-1.
The Diamondbacks added an unearned run on second baseman Descalso's throwing error in the fifth. Prado, acquired from Atlanta in the Justin Upton trade, doubled to deep right-center, then Aaron Hill hit a slow grounder to second. Descalso threw in the dirt trying to throw to first and the ball bounced off the glove of first baseman Allen Craig as Prado raced home to make it 4-1.
Arizona got two more in the seventh. With Fernando Salas on the mound, Parra and Prado doubled, then Hill singled. Marc Rzepczynski relieved Salas and gave up an RBI sacrifice fly to Montero.
Notes: Entering the game, Kennedy was 1-3 against Cardinals with an 8.59 ERA. ... Kennedy was the winning pitcher when Arizona beat San Francisco in its season opener a year ago. .. Former Diamondbacks ace Brandon Webb, whose career was cut short by arm trouble, threw out the ceremonial first pitch. ... Wainwright made his second career opening day start. ... The Cardinals send left-hander Jaime Garcia to the mound Tuesday night while the Diamondbacks go with right-hander Trevor Cahill. ... The only other Arizona rookie with three hits on opening day was Travis Lee, who did it in the Diamondbacks' first game in 1998. ... Attendance was a sellout of 48,033.
Manchester police and the FBI are asking for help identifying a man they believe spiked the soup the Dierbergs at Lafayette Center. Employees pulled the soup container on Thursday, after witnesses saw a man pouring a foreign substance into the container near the salad bar. The soup was removed before any was purchased. The soup-spiker was caught on surveillance video before he could make his escape. He's described as a Caucasian man between 50 and 60 years old with a heavy build and light beard.
A standing-room only crowd will have to come back another night to see the conclusion of Ellisville Mayor Adam Paul's impeachment hearing. Proceedings lasted for a little more than six hours last night. Hundreds of residents and spectators packed the Ellisville Elementary School gymnasium, which was chosen to host the event because of the expected size of the crowd. Ellisville City Counsel members are seeking to remove the 32-year-old Mayor for office, claiming he abused and overreached his authority. Paul's lawyer Chet Pleban unsuccessfully tried several methods to get the hearing thrown out. Pleban says the counsel is biased and the lawyer for the prosecution was illegally chosen. All of Pleban's objections were overruled. The hearing is scheduled to resume tonight at 7:00.
(ST. LOUIS) – St. Louis Blues General Manager Doug Armstrong announced Monday the club has acquired defenseman Jay Bouwmeester from Calgary in exchange for minor league defenseman Mark Cundari, the rights to goaltender Reto Berra as well as a conditional 1st round pick in 2013. If the Blues miss the playoffs this season, the Flames will receive the Blues' fourth round pick in the 2013 NHL Entry Draft and St. Louis' first round pick in the 2014 draft.
“We've been looking to acquire a top left handed defenseman and Jay represents that and is an elite player in our game,” said Armstrong.
Bouwmeester, 29, has dressed in 33 games for the Flames this season posting 15 points (six goals, nine assists) and 16 penalty minutes while ranking 13th among all defenseman in time on ice per game (25:09). The 6’4, 212-pound defenseman has appeared in 10 National Hockey League (NHL) season, including stints with Florida and Calgary, recording 300 points (71 goals, 229 assists) and 463 penalty minutes in 750 career games. In addition, Bouwmeester has played in 621 consecutive NHL games.
The Edmonton, Alberta native was originally drafted by Florida in the first round (3rd overall) of the 2002 Entry Draft. Bouwmeester will not count against the Blues 23 man roster until he clears through immigration procedures.