CINCINNATI -- Despite the increasing pressures of a pennant race, St. Louis Cardinals rookie right-hander Luke Weaver is gaining confidence with each start.

Weaver hasn't lost a game in nearly two months, and he now owns the longest winning streak for a Cardinals rookie since 1944.

Matt Carpenter, Dexter Fowler and Paul DeJong homered, and Weaver allowed two runs through five innings to lift the Cardinals to a 9-2 victory over the Cincinnati Reds on Wednesday night at Great American Ball Park.

Weaver (7-1) struck out seven and did not walk a batter to extend his major-league-leading win streak to seven games. He hasn't lost a start since July 27.

"I've had good nerves building up with each start," Weaver said. "We're playing in a lot of meaningful games. I just don't want to put too much pressure on myself."

Ted Wilks won seven straight games as a rookie in 1944. Matt Morris is the last St. Louis pitcher to do it, in 2001.

"For a young guy, he doesn't make a lot of mistakes in the middle of the plate," Cardinals manager Mike Matheny said of Weaver. "He's making quality pitches. It is fun to watch."

Weaver had been tied with Adam Wainwright at six straight wins. Weaver has struck out six or more batters in each of his past seven starts.

On Wednesday, his pitch efficiency wasn't as good as it has been with 87 pitches through five innings, but Weaver was able to overcome some command issues with a good mix of three pitches.

"The fastball came out of his hand as good as we've seen," Matheny said. "He got in some deep counts. But he got the big strikeout when he needed it. He used his curveball as well as he's used it. He made pitches on both sides of the plate."

For the second straight night, the Cardinals' offense came through.

Tommy Pham went 3-for-5 with two doubles and two RBIs for St, Louis (79-72), which trails the first-place Chicago Cubs by five games in the National League Central standings. St. Louis is 2 1/2 games behind the Colorado Rockies for the second NL wild-card spot.

Yadier Molina and Fowler each had two RBIs to help hand Cincinnati (66-86) its second straight loss to begin the series.

Four Cardinals relievers combined to retire 12 of the final 13 Reds batters to finish off the win.

Reds starter Rookie Davis (1-3) lasted only three innings, allowing five runs and five hits.

"These guys (Cardinals) are in the thick of things so you want to throw a quality start," Davis said. "You want to beat them. I didn't force early contact when I needed to."

In the first inning, Carpenter launched a 3-2 pitch from Davis into the right field seats for his 21st home run of the season. It was his 14th career leadoff homer, second this season.

In the third, Pham doubled in a run and Fowler followed with his career-high 18th home run, making the score 4-0. Fowler has homered in three straight games.

"They saw too many pitches and put the barrel of the bat on the ball," Reds manager Bryan Price said. "This is a whole different environment up here. The games count. The stats count. I watched Rookie's last bullpen. He couldn't have thrown the ball any better."

Things went further downhill for Davis when DeJong's 24th home run immediately followed Fowler's. It was the 10th set of back-to-back home runs allowed by Reds pitchers this season.

Molina's bases-loaded double off Keury Mella, who was making his major league debut, made the score 7-0 in the fifth.

Cincinnati broke up the shutout with two runs in the fifth on Patrick Kivlehan's RBI double and an RBI hit by Jesse Winker, making it 7-2.

But the Cardinals' bullpen shut the door, handing Weaver his seventh win.

"Everything is trending in the right direction, that's a positive thing for me," Weaver said.

NOTES: The Cardinals recalled INF Aledmys Diaz and RHP Josh Lucas from Triple-A Memphis. ... Reds CF Billy Hamilton was reinstated from the 10-day disabled list. He has been sidelined since Sept. 7 with a fractured left thumb. He likely will be used initially as a pinch runner. ... Cardinals RHP Jack Flaherty will move to the bullpen and RHP John Gant will join the rotation, manager Mike Matheny announced before the game. ... Cincinnati pitchers have allowed four leadoff homers this season. ... Reds C Chad Wallach singled as a pinch hitter in the ninth inning for his first career hit.