ST. LOUIS -- Nothing bothered Zach Godley on Thursday night.

Not a 62-minute rain delay before the first pitch, not a St. Louis Cardinals offense that had scored 21 runs in a three-game sweep of Colorado, and not even the rare times he had to pitch under stress.

The Diamondbacks right-hander fired seven shutout innings as he got his team off to a good start on a critical 10-game road trip, leading Arizona to a 4-0 victory at Busch Stadium.

J.D. Martinez's fourth-inning grand slam provided all of the runs.

Godley (4-4) permitted just four hits and two walks while striking out seven. He threw 66 of his 105 pitches for strikes and fetched a dozen groundball outs. Of the 21 outs he recorded, none of them left the infield.

"He definitely had good command of the sinker," Arizona catcher Chris Iannetta said of Godley. "He was also throwing the curve at will for strikes."

As his teammates took a pass through the batting order to figure out St. Louis starter Luke Weaver, Godley gave them time to settle in. Godley ceded a pair of one-out singles to Tommy Pham and Paul DeJong in the first, then induced a 5-3 double play bouncer from Randal Grichuk.

In the third, after Greg Garcia led off with a single and reached second on a two-out wild pitch, Godley reached a full count with Pham. He threw a breaking ball, and Pham flailed to no avail, the third strikeout of the inning.

"That was a really impressive outing," Arizona manager Torey Lovullo said of Godley. "When you walk into a tough environment against a team that's been playing well, you're looking for big push moments early. He gave us one."

After matching Godley through three innings, Weaver flinched in the fourth. A.J. Pollock led off with a double to right-center. Pitching carefully to Jake Lamb and Paul Goldschmidt, Weaver issued consecutive walks.

That filled the bases with no outs for Martinez. Weaver obtained two quick strikes, but Martinez spoiled a fastball off the plate and laid off a changeup.

Weaver tried a fastball on the outside corner. Martinez lofted it down the right field line, and the ball curled inside the foul pole for the fourth grand slam of his career. It was his fourth Diamondbacks homer since being acquired from Detroit on July 18 and his 20th homer of the year.

"That's an impressive approach to hit the ball that far with two strikes," Lovullo said of Martinez. "Our guys started to share some info and rely on one another. We hadn't seen (Weaver) at all."

That pitch ruined the night for Weaver (0-1), who drew the start when Adam Wainwright hit the 10-day disabled list Tuesday due to mid-back tightness. Weaver lasted five innings, allowing five hits and four runs with two walks and four strikeouts.

The Cardinals (50-52) pushed only one baserunner to third. Rookie Harrison Bader hit with men at first and third in the sixth. Godley threw three breaking balls off the plate, and Bader swung at all of them, including the curveball that ended the inning.

"I felt like he had everything working," St. Louis manager Mike Matheny said of Godley. "He probably had one of the sharpest breaking balls we've seen all year. He had enough sideways movement on his fastball to keep you honest."

While the Cardinals fell 4 1/2 games behind the first place Chicago Cubs in the National League Central, Arizona (59-43) increased its lead on the Rockies for the league's first wild-card spot to 1 1/2 games.

Godley was the catalyst.

"The sinker worked really well, and to keep getting ground balls was awesome," he said. "I felt really good."

NOTES: To make room for Thursday night's starting pitcher, RHP Luke Weaver, St. Louis optioned RHP Mike Mayers back to Triple-A Memphis. Mayers was recalled Wednesday to take the place of RHP Adam Wainwright (back) on the 25-man roster. ... Arizona acquired C John Ryan Murphy from Minnesota for LHP Gabriel Moya and sent Murphy to Triple-A Reno. Murphy, a former New York Yankee, batted .222 with four homers and 27 RBI in 59 games at Triple-A Rochester. ... Cardinals RF Stephen Piscotty (right groin strain) started a rehab assignment Thursday night for Class A Peoria, going 0-for-3 before leaving the game after four innings.