SAN DIEGO -- With Carlos Martinez in the right mindset, the San Diego Padres had little chance.

The Cardinals right-hander threw his second shutout of the season, and Yadier Molina hit a two-run single as St. Louis beat San Diego 2-0 on Monday.

"I really attribute my winning today (to) just the ultimate concentration," Martinez said through a translator after tossing a three-hitter. "I was focused and I was concentrated on my secondary pitch, which is my slider."

Molina's big hit came in the fourth inning as the Cardinals won for the fourth time in five games as they try to stay within striking distance of a playoff berth. St. Louis is three games behind the Colorado Rockies for the second National League wild card.

Martinez (11-10) won for the fourth time in his past six outings as he was seldom challenged by the Padres, who managed only three singles. San Diego never had two runners on base in the same inning and never got a runner in scoring position. Martinez struck out 10 and walk three while throwing 109 pitches.

"We needed him to finish what he started there," Cardinals manager Mike Matheny said. "He was so efficient through the game. It was one of those days where everything was going. He had a great fastball, and his slider was terrific. It was impressive to watch."

Luis Perdomo (7-9) took a fourth loss in his past six decisions. He pitched six innings and surrendered two runs on seven hits with three walks. He struck out six while going at least six inning for a his ninth straight start.

"His only real jam came when he allowed those two runs," Padres manager Andy Green said. "His stuff was coming in great."

Martinez produced his third nine-inning effort on this season, and it was the second one that he won. He didn't get a decision when going nine against the San Francisco Giants on May 2, as the Cardinals lost in 13 innings. Martinez threw his first career shutout when stopping the Philadelphia Phillies on four hits on June 10.

When Matheny asked if Martinez was tired in the eighth, the pitcher shook his head in the negative.

"I said, 'No, I'm going to finish my game.' That was my way of showing I'm not tired," Martinez said.

The Padres, who just took three of four from the Los Angeles Dodgers, had their three-game winning streak snapped.

St. Louis loaded the bases in the fifth when Perdomo struggled with his command. Randal Grichuk began the frame with a walk, and Tommy Pham singled. Perdomo walked Paul DeJong to load the bases. However, Jose Martinez's fly to center field was caught at the base of the fence by Manuel Margot.

The Cardinals struck in the fourth to score the only runs.

Molina had the big hit, although it came with an assist. After Pham opened with a single and advanced to second on DeJong's walk, Molina lifted a fly ball to left fielder Jose Pirela. After a long run, Pirela had the ball glance off his glove to score Pham and DeJong. Molina generously was credited with a hit.

"That is in the tough-play category," Green said. "But Jose probably thinks he should make that play, but it wasn't an easy catch. He ran a long way for it."

In the long run, it cost the Padres a game and Perdomo a possible win. But Perdomo shrugged when he asked if he thought Pirela should have snagged Molina's drive.

"Not really," Perdomo said through a translator. "That could happen in any game, a play like that."

NOTES: Cardinals 3B Matt Carpenter was replaced in the fifth inning because of a sore shoulder. LF Tommy Pham exited in the seventh, also with a sore shoulder after getting injured on a slide. ... Cardinals OF Dexter Fowler (hip) did not play, although he was available to pinch-hit. ... Cardinals INF Kolten Wong (back) also sat out. .. Padres OF Jabari Blash had struck out eight consecutive plate appearances before flying out in the seventh inning. ... The Padres played their fifth game in 70 hours.