The St. Louis Cardinals welcomed back ace Chris Carpenter to the mound but missed a chance to tighten their grip on a National League wild card spot falling 5-4 to the Chicago Cubs in an extra-inning thriller at Wrigley Field on Friday.
Carpenter, back on the hill for the first time since Game Seven of last year's World Series, was solid in his season debut giving up two runs on five hits in five innings of work.
But the World Series champions still watched their hold on the second wild card trimmed to 1.5 games by the Milwaukee Brewers, who were winners over the Washington Nationals.
Leading 4-2 heading into the bottom of the ninth, Carpenter looked set for a winning return until Cubs Darwin Barney slammed a two-run homer that sent the contest into extra innings, setting the stage for David DeJesus, who delivered the game winning single in the 11th.
Despite the loss, Carpenter's performance was a big boost for the Cardinals, who add an experience right arm to their rotation as they continue their push for post-season berth.
"My stuff wasn't as sharp as I'd like, it wasn't even as sharp as it's been in those simulated games," Carpenter, who underwent surgery in July for thoracic outlet syndrome that was causing numbness on his right side, told reporters. "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."
The Cardinals could use the help as pressure continues to mount in a tight NL wild card race.
The surging Brewers kept the heat on St. Louis as they recorded their sixth straight win pushing across three runs in the ninth to beat the Nationals 4-2.
Matt Kemp's two-run single with two outs in the top of the 10th inning lifted the Los Angeles Dodgers to a 3-1 win over the Cincinnati Reds, to keep them in the post-season chase just two back of Cardinals.
Kemp's heroics denied Reds fans a party, with Cincinnati looking to clinch the NL Central crown after having already secured at least a wild card spot on Thursday.
Lurking three games back are the Philadelphia Phillies, who slammed four solo home runs on way to a 6-2 victory over the Atlanta Braves, owners of the first NL wild card.
Over in the American League, the New York Yankees and Baltimore Orioles continued their tug-of-war at the top of the East division with 12 games left in the regular season.
Russell Martin crushed a walk off homer to open the 10th inning as Yankees ran their winning streak to six edging the Oakland Athletics 2-1 while the Orioles kept pace with 4-2 decision over the Boston Red Sox.
With the victory, the Yankees were able to maintain a one game lead over the Orioles, who hold down the first AL wild card spot ahead of the slumping Athletics, losers of four of their last five.
The Tampa Bay Rays kept their dimming playoff hopes alive crushing the Toronto Blue Jays 12-1 to sit 4.5 back of a playoff spot.
The Los Angeles Angels stayed in the hunt for post-season action with a 6-2 win over the AL Central leading Chicago White Sox.
Mike Trout and Kendrys Morales both had home runs for the Angels who moved within 3.5 games of Oakland while the White Sox were left looking over their shoulders at the Detroit Tigers, who now sit just 1.5 back.
The Tigers had their game with Minnesota Twins postponed because of rain.
(Reporting by Steve Keating in Toronto; editing by Amlan Chakraborty)