ST. LOUIS -- Seattle rookie left-hander James Paxton was so locked in on Saturday night that he failed to notice the loud, sellout crowd at Busch Stadium.
At least until his night was done.
"When they took me out of the game, I got on the bench and said to myself, "Wow, there's a lot of people here."
Yes, Paxton was that focused.
In his second major league start, Paxton tossed six shutout innings and Kendrys Morales homered to lift the Mariners to a 4-1 win over the St. Louis Cardinals.
Franklin Gutierrez added a two-run double for Seattle, which broke a five-game losing streak.
St. Louis has lost two of three and fell into a tie with Pittsburgh for first place in the National League Central.
Paxton allowed two hits and struck out five. He retired the first eight batters and set the side down in order four times.
"He's pitching in a very mature fashion," Seattle manager Eric Wedge said. "Big crowd, against a tough ballclub in the middle of September, it was nice to see him step up like that."
The Canadian-born Paxton improved to 2-0 and lowered his ERA to 0.75.
"I just tried to put my fastball in there in the bottom of the zone," he said. "My changeup was working too and I was working off that."
A former University of Kentucky standout, Paxton surrendered one run and four hits in six innings in his debut -- a 6-2 win over Tampa Bay on Sept. 7.
"It's the most relaxed, the best I've seen him pitch since I caught him," catcher Mike Zunino said. "Right now, he's just going out there and competing and he has a lot of confidence."
Paxton also scored in the two-run fifth inning. Batting for the first time since he was 14 years old, he coaxed a four-pitch walk from St. Louis rookie starter Michael Wacha (3-1). Paxton scored on Gutierrez' double right behind Dustin Ackley, who begin the rally with a leadoff singe.
"I'm not much on running, I decided I'd just watch Dustin and do what he did," Paxton said.
Paxton's scamper around third base left a little to be desired. He took plenty of good-natured ribbed from his teammates in the dugout after scoring the run.
Seattle relievers Danny Farquhar, Tom Wilhelmsen and Charlie Furbush kept the Cardinals under wraps the rest of the way. Farquhar picked up his 14th save in 16 chances. The four pitchers held the Cardinals to just three hits.
Morales hit his 22nd homer of the season, off reliever Tyler Lyons, in the eighth to push the lead to 3-0. Morales has four homers in his last eight games.
Gutierrez proved all the necessary support with his two-run double off Wacha. Ackley singled to start the rally. Paxton drew a walk on four pitches. Brad Miller moved the runners over with a perfect bunt to set up Gutierrez' blow down the left-field line, which came on the first pitch.
"I just went up there and on the first pitch, I said, "he's throwing a fastball," Gutierrez said. "It was huge in that situation."
The two-run outburst broke Wacha's scoreless streak of 23 2/3 innings. Wacha (3-1) allowed two runs and four hits in five innings. He struck out seven but walked a season-high four.
"I just wasn't able to command my stuff out there," Wacha said. "I wasn't in sync."
The Cardinals' lone run came on the eighth on a wild pitch by Furbush. Matt Carpenter doubled and came in to score with two out.
Seattle pushed the lead to 4-1 on a sacrifice fly by Carlos Triunfel in the ninth. Triunfel replaced Miller at shortstop in the fifth. Miller was diagnosed with a mild left hamstring strain.
"At least a couple days," Wedge said.
The Mariners loaded the bases with one out in the third. But Wacha fanned Gutierrez and Kyle Seager to end the threat. Zunino and Ackley drew leadoff walks and Miller singled to right with one away.
Wacha got the first hit off Paxton with two out in the third on a grounder to the right of the mound that Paxton was not able to handle. Carpenter then drew a walk, but Paxton induced Shane Robinson to ground out to end the threat.
NOTES: Reliever Trevor Rosenthal was back at Busch Stadium after missing the last two games. His wife, Lindsey, delivered the couple's first child, a girl, Chloe, on Friday. ... Friday night's walk-off win on a passed ball marked the first time the Cardinals had won a game in that manner since June 5, 1979. ... The loss also was a franchise-record 13th defeat in extra innings for the Mariners this season and was their 12th walk-off loss. ... Matt Carpenter is one double from becoming the first Cardinal to hit 50 or more doubles in a season since Albert Pujols had 51 in 2004. ... The Cardinals and Mariners will conclude the three-game series on Sunday afternoon as Shelby Miller (13-9, 3.05 ERA) will pitch for the Cardinals against the Mariners' Erasmo Ramirez (5-1, 4.57 ERA). ... Miller has 27 multi-hit games, third on the team. He did not make his season debut until June 28.