"Unbelievable," catcher Yadier Molina said of his teammate's night. "What a game for him."
For Jake Westbrook, too, who tossed seven scoreless innings en route to his fourth win of the season. The stage, however, was stolen early by Beltran, who, beginning with last week's two-homer game and continuing through this one, has 10 hits in his last 23 at-bats.
That followed a well-documented skid in which he tallied only three hits -- none of which left the park -- in a string of 32 at-bats. There is no longer talk of such a slump.
"I feel a little better at the plate," Beltran said of his recent upward turn. "It's confidence. It's results. It's a little bit of everything."
Beltran's first blast followed Jon Jay's leadoff triple and was deposited in the back rows of the right-field lower deck seats. It followed a night in which the Cardinals belted five homers.
It also staked Westbrook to an early lead, something that has become the norm. Not only have the Cardinals scored first in 22 of 30 games this year, but Westbrook has been the beneficiary of the most support.
He entered the night averaging 8.21 runs of support per game, the largest such average in the National League.
"It lets you settle down and go after guys and be more aggressive, which is what I'm trying to do anyways," Westbrook said. "Hopefully we can continue that trend."
Beltran padded Westbrook's cushion considerably in the second, slugging his 10th career grand slam on a 2-1 pitch from Arizona's Ian Kennedy. The inning had just been extended when Westbrook drew a two-out walk and Jay followed by being hit by a pitch.
Thirty-nine pitches into his night, Kennedy, who had gone 10-0 with a 2.27 ERA in his previous 14 starts at Chase Field, was staring into a six-run hole.
"I felt early in the game that he was leaving balls over the plate," Beltran said. "Later in the game he was hitting the corners and his spots like he normally does. We took advantage of the opportunities, and after that, Westbrook was able to go out there and pitch a good game."
The multi-homer game was the 32nd of Beltran's career and thrust him toward the top of the NL in several offensive categories. Beltran, with 10 home runs, trails only Los Angeles' Matt Kemp (12) in that list. Beltran ranks third with 26 RBIs and second with 23 runs scored.
Kennedy calmed things from there, allowing only two other baserunners in his next five innings. He ended his outing by retiring 13 straight.
Westbrook was that good for his full seven-inning start. Limiting the D-backs to four singles, Westbrook had only one inning in which he had to deal with more than one baserunner. He struck out a season-high eight and threw 72 of his season-high 115 pitches for strikes.
"I felt really good today," Westbrook said. "That's probably the best I've felt all year physically."
Though Westbrook has hardly struggled this season, Tuesday's start did come on the heels of his rockiest one in this young season. Unable to get ideal movement on his pitches, particularly his sinker, against Pittsburgh last week, Westbrook not only pitched with crisp movement, but with sharp command, too.
Complementing that sinker with an effective changeup and slider, Westbrook cruised.
"It was the kind of pitching that we've seen from Jake since start one of Spring Training all the way up until his last game," manager Mike Matheny said. "Right back into his style of pitching, giving our infielders a lot of work."
Westbrook, who has pitched into the seventh in each of his six outings, has won all four of the games he has started against teams not from Pittsburgh. It took Westbrook 10 starts before he notched his fourth win in 2011.
The victory was the Cardinals' second straight in a series pitting half of last year's NL postseason representatives. To this point, the Cardinals have dominated. They haven't trailed and their starting pitching has strung together 12 scoreless frames.
"Plain and simple, St. Louis is playing better than us," D-backs manager Kirk Gibson said. "They beat us in every aspect of the game."
The only run scored by Arizona on Tuesday came off reliever Mitchell Boggs in the ninth. That inning was further marred by an injury to Molina, who, expecting a slider from Boggs, was struck on the left wrist by a 96-mph fastball. Preliminary X-rays came back showing no signs of a fracture, though the Cardinals will re-evaluate on Wednesday.
With the victory, the Cardinals give themselves yet another shot at closing out a series sweep. Though they have now won nine of 11 series, St. Louis will enter Wednesday 0-4 after winning the first two games of a series.