ST. LOUIS -- Leading off the bottom of the 10th inning Monday, St. Louis Cardinals shortstop Jhonny Peralta wasn't thinking about a game-winning homer.

"I'm thinking about making contact," Peralta said.

Peralta not only made contact, he sent J.C. Ramirez's slider 364 feet to the front row in the left-field seats, lifting St. Louis to a 3-2 win over the Arizona Diamondbacks at Busch Stadium.

It was the seventh homer of the season for Peralta and the fourth walk-off homer of his career, enabling the Cardinals (29-16) to start a nine-game homestand with their fifth extra-inning win of the year.

St. Louis rapped out 15 hits off five Arizona pitchers, but the Cardinals were just 2-of-11 with runners in scoring position.

They could have ended the game in the ninth, but Ramirez fanned third baseman Matt Carpenter, left fielder Matt Holliday and first baseman Matt Adams after Enrique Burgos yielded leadoff singles by center fielder Randal Grichuk and second baseman Kolten Wong.

However, Ramirez (1-1) left his last pitch over the plate's heart, and Peralta sent the crowd of 42,853 home happy.

"I thought I hit it pretty well," Peralta said. "I knew the pitcher from facing him in the American League. With two strikes, he's going to throw a slider. He hung it."

Closer Trevor Rosenthal (1-0) worked two innings for the win, escaping a bases-loaded, one-out jam in the top of the 10th. After a mound visit from manager Mike Matheny, Rosenthal slipped a 100 mph fastball by second baseman Chris Owings for a called third strike, then induced a groundout from catcher Tuffy Gosewisch.

Matheny said his message to Rosenthal wasn't to reach back for anything extra, even though Rosenthal's six pitches after the visit were clocked between 98 and 100 mph.

"He's having a great season," Matheny said of Rosenthal, who lowered his ERA to 0.81. "You're seeing him attack the hitters; and, overall, I don't know that you can ask for too much more than what he's done."

In losing for just the second time in eight games, the Diamondbacks (21-23) missed out on their share of chances with men in scoring position, going just 1-for-10. While the 10th inning was a glaring failure, the eighth inning was also damaging, even though they rallied to tie the game.

After right fielder Mark Trumbo rifled a two-run homer to center off reliever Kevin Siegrist, Arizona got consecutive walks from first baseman Paul Goldschmidt and right fielder David Peralta.

Reliever Seth Maness cleaned up Siegrist's mess. Third baseman Yasmany Tomas flew out to right, Owings bunted the runners into scoring position and Gosewisch fanned on three pitches.

"It's one of those things you've got to learn how to do as a group," Diamondbacks manager Chip Hale said of converting scoring opportunities. "Hitters have to be able to put the ball in play with one out and a man at third. It's something we just need to get better at."

St. Louis initiated scoring in the bottom of the first on a fielder's choice grounder by Adams. It scored Wong, who had led off with a double and reached third on a single by Carpenter.

Right fielder Jason Heyward upped the Cardinals' lead to 2-0 in the fourth with a two-out RBI single off the glove of shortstop Nick Ahmed, plating Adams.

St. Louis starter Carlos Martinez tied a career high with eight strikeouts over seven scoreless innings, the second straight outing in which he has not allowed a run. Martinez gave up just five hits and walked two in a 97-pitch effort.

"It's a shame we couldn't hold it for him," Matheny said. "He made some tough pitches when he had to. He had some of the consistency today that we've wanted to see."

Arizona starter Chase Anderson scattered 10 hits over six innings, allowing two runs. Anderson walked one and fanned four.

NOTES: St. Louis CF Jon