CHICAGO -- On a day when they received an emotional boost from the much-anticipated return of an ace starter, the Cardinals missed a chance to extend their winning streak to five games through an inability to find a capable closer.
With closer Jason Motte and setup man Mitchell Boggs relegated to spectator status because of recent overuse, manager Mike Matheny turned to Fernando Salas to hold a 4-2 lead in the ninth. Twice one strike away, Salas let the Cubs back in.
Two innings later, Chicago completed its comeback against Joe Kelly to stun the Cardinals, 5-4, at Wrigley Field. For St. Louis, the loss cuts into their lead for the second National League Wild Card spot. Milwaukee, after beating the Nationals on Friday night, now trails by 1 1/2 games.
"It was an unfortunate loss," said Chris Carpenter, who pitched under overcast skies and through constant rain. "Those things happen. We were one pitch away. These guys battled. It was tough conditions and a tough day."
This was an all-too-familiar ending for the Cardinals. Their most recent defeat also came after twice putting their opponent one strike away from defeat. That was last Saturday in Los Angeles.
And of the Cardinals' last seven losses at Wrigley Field, five have been walk-offs
"A loss is a loss, walk-off or not walk-off," Daniel Descalso said. "We have to find a way to win these games."
Carpenter has pitched on stages much bigger and against clubs substantially better than this 92-loss contingent from Chicago. Yet, none of the right-hander's 330 career regular-season starts has been as long anticipated as this.
Carpenter made his season debut, less than three months after the organization had declared his season over because of upcoming surgery to address thoracic outlet syndrome. His return Friday wasn't without rust, but Carpenter, whose last start came 330 days ago, left after the fifth in line for the win.
"My stuff wasn't as sharp as I'd like, it wasn't even as sharp as it's been in those simulated games," said Carpenter, who preceded this start with four simulated games. "I did the best I could to get as many outs as I could and give us a chance. It was fun to go out there. It's definitely something I can build on, and hopefully my stuff is sharper as I get out there more often."
Carpenter needed 18 pitches to get through the first, which was blemished only by a walk. He gave up his first hit in the second before stranding two.
Chicago hit several hard balls in the third, and that translated into a game-tying two-run inning. David DeJesus led off with a triple and scored on Darwin Barney's single to center. Two batters later, Alfonso Soriano doubled home a run.
"Obviously, I've seen him with much better stuff and sharpness," Cubs manager Dale Sveum said. "I think he got away with a lot of things today."
Carpenter pitched much of the afternoon without great feel for his curveball. Nor did he rely as heavily on his cutter as he often does.
But Carpenter finished his outing by retiring eight of the final nine batters he faced. He threw 47 of his 77 pitches for strikes and walked only one. While Carpenter induced just three swings and misses, he did notch two strikeouts.
Giving the Cardinals no reason to unplug him from the rotation, Carpenter can make two more starts for the club before the end of the regular season.
"It's good to have him back out there," Matheny said. "He did exactly what we thought he would do. He went out to compete and made some good pitches. He gave us a chance to win."
It was the bullpen that couldn't preserve it.
Shelby Miller, Sam Freeman, Trevor Rosenthal and Edward Mujica all worked around baserunners to preserve the Cards' 4-2 lead heading into the ninth. Motte was unavailable after pitching in five straight games. Boggs, who had pitched in three consecutive ones, was also off limits.
That forced Matheny to delegate closer duties elsewhere, and he told Salas before the game that he'd be the one called upon. Salas, scored on in just two of his previous 20 appearances, retired the first two batters. DeJesus extended the inning with a two-strike single. Barney followed with a home run on a 1-2 changeup.
"That's my best pitch," said Salas, who saved 24 games in 2011. "I threw the pitch that I wanted. He made good contact."
After pitching a scoreless 10th, Kelly allowed an 11th-inning leadoff single Welington Castillo. Three batters later, DeJesus delivered the game-ending single.
"I liked the pitch selection," Kelly said of his 0-2 changeup. "I maybe threw it too hard and left it up. I wanted to get it way off the plate or down -- I was going way off the plate -- and left it more on the corner in the middle."
The loss exposed the Cardinals' inability to do more on offense early against Cubs starter Chris Volstad, who needed 116 pitches to get through five innings. He put nine on base but limited the Cardinals to three runs.
Yadier Molina delivered a two-out single in the first to score Jon Jay. The Cardinals pushed their lead to two with Allen Craig's sacrifice fly in the third.
After the Cubs evened the game, the Cards pulled ahead with a squeeze attempt-turned-steal of home in the fourth. Though Descalso was unable to bunt a high-and-tight pitch, Castillo couldn't block it. Pete Kozma, dashing home from third, scored easily.
Descalso's RBI double in the eighth ran the Cards' lead back to two. That was the only hit the Cardinals collected in eight at-bats with a runner in scoring position. The club stranded 11.
Said Matheny of the missed chances: "They always do come back and haunt you."
Jenifer Langosch is a reporter for MLB.com. Read her blog, By Gosh, It's Langosch, and follow her on Twitter @LangoschMLB. This story was not subject to the approval of Major League Baseball or its clubs.