PITTSBURGH -- The Pirates and Cardinals went back and forth as their bullpens put up a steady line of zeros late into the evening. Pittsburgh finally sent everyone home in the 11th inning on a chilly Tuesday night at PNC Park, as Jordy Mercer's walk-off single to right field gave the Bucs a 6-5 win over St. Louis.
The National League Central rivals met 19 times last season, and five of those games went into extra innings, all of them decided in walk-off fashion. They played seven one-run games. Their bullpens were the two best in the NL. Two games into the season, there's reason to believe not much has changed in 2016.
"It seems like we always play these guys, they're good games and we always go to extra innings or something crazy happens," Mercer said. "Just two good teams going at it."
• Bauman: Pirates win battle of best NL bullpens
The Cardinals' bullpen -- from Tyler Lyons in the fifth to Seth Maness in the 11th -- had retired 18 straight batters when Gregory Polanco came to the plate with one out in the final inning. Maness walked Polanco, and Josh Harrison's single up the middle moved Polanco to second. Mercer then delivered a base hit down the right-field line that slipped past Cards first baseman Matt Adams.
"It was unbelievable," Cardinals starter Michael Wacha said of watching what his bullpen did after he exited with one out in the fifth. "Those guys were throwing up zeros after zeros. They kept us in there, gave us a fighting chance. It was a lot of fun watching those guys go to work."
"I know it was cold," Mercer said of the mid-30s chill by the Allegheny River. "So we were ready to get the heck out of there."
Making his Pirates debut, left-hander Jonathon Niese gave up five runs (four earned) on five hits and a walk while striking out seven. Niese pitched better than his line might indicate, as Pittsburgh made a few costly mistakes behind him, but St. Louis capitalized on two mistakes by Niese in the fourth. Niese hit Brandon Moss with a pitch, then served up a two-run homer to Jedd Gyorko, the second baseman's first with the Cardinals.

As well as the Cardinals' bullpen pitched, the Pirates matched them after Niese left the game. Five relievers combined to throw six scoreless innings, allowing three hits and two walks while striking out six. Left-hander Kyle Lobstein picked up a win by tossing two scoreless innings to end the game.
"We didn't give up a run all the way through," Pirates manager Clint Hurdle said. "All of them contributed."

MOMENTS THAT MATTERED
Mixed review: Aledmys Diaz wasted no time collecting a hit in his Major League debut, but he also committed a defensive flub that turned the game in the fifth. Two innings after he laced a single to right, Diaz received a grounder off the bat of Francisco Cervelli with the bases full, one out and the Cardinals clinging to a 5-3 lead. But what was a tailor-made double-play ball was bobbled by Diaz, who couldn't get an out. Wacha was chased from his start, and the Pirates evened the game before the inning ended. More >
"I was thinking about making a double play for the team," Diaz said, "and I think I hurried up a little bit and missed the ball."

Corner misplays: The Pirates' corner outfielders didn't do Niese any favors, playing a part in at least two Cardinals runs. In the third inning, left fielder Starling Marte bobbled Stephen Piscotty's single, allowing Diaz to score, Matt Carpenter to reach third and Piscotty to take second. Carpenter immediately came around to score on a groundout by Matt Holliday. In the fifth, right fielder Polanco took an indirect route into the right-center-field gap, turning what was likely a double by Piscotty into a triple. Piscotty scored on the next play, another defensive miscue, when Mercer threw wide of John Jaso at first.

On the mark: After misreading a ball off the right-field wall in the Pirates' two-run second, Cardinals right fielder Piscotty halted a potential Pittsburgh rally in the third by throwing Andrew McCutchen out at home. Yadier Molina made the swipe tag on McCutchen, who was trying to score from second on a single by David Freese. Piscotty also reached base three times and collected the team's first triple of the season.
"Terrific play, on both ends of that," Cardinals manager Mike Matheny said. "That was a plus-plus throw to get a very fast runner."

$35-million man: Fresh off a news conference announcing his newly signed long-term extension with the Pirates, Polanco ripped an RBI triple off the Clemente wall -- with a 110-mph exit velocity, according to Statcast™ -- in the second inning to give Pittsburgh an early 1-0 lead. Harrison followed with a productive out, knocking a grounder to shortstop that allowed Polanco to score from third.

UPON FURTHER REVIEW
The Cardinals unsuccessfully challenged a safe call on a bang-bang play at second base in the bottom of the 11th. Gyorko, who had moved over to short, made a diving stop to glove a Harrison ground ball and rolled the ball to second baseman Kolten Wong, who grabbed it as Polanco was sliding into second. Polanco was called safe, a ruling that was confirmed via instant replay. It turned out to be a key call, too, as Polanco came home as the game-winning run five pitches later.
"It kind of got stuck in my glove a little bit," Gyorko said. "I made that play like a week ago down in Florida. It's in there. I just have to get it out of my glove a little bit smoother."

QUOTABLE
"That's what I wanted to do. I wanted to get the whole team in here and get warm." -- Mercer
"You've seen him on video, seen him on tape, and try to prepare as best you can. [He threw a] tough first-pitch cutter, tough second-pitch curveball. And then I just battled after that and was able to get some wood on that pitch and get it down the line. A lot of excitement. It's a great accomplishment, absolutely." -- Cardinals outfielder Jeremy Hazelbaker, on collecting his first Major League hit off Mark Melancon.
SOUND SMART WITH YOUR FRIENDS
The last time the Cardinals opened a season 0-2 was also the last time the franchise won a World Series -- 2011. That club actually lost six of its first eight games.
Tuesday was the first time since Aug. 13, 2014, that the Pirates entered the day ahead of the Cardinals in the standings.
WHAT'S NEXT
Cardinals:Mike Leake will make his organizational debut on Wednesday when the Cardinals wrap up their series in Pittsburgh with a 6:05 p.m. CT game at PNC Park. Leake, who allowed five runs in 20 spring innings, received the largest contract the Cardinals have ever given to a free-agent pitcher.
Pirates: After earning a spot in the rotation with a sensational Spring Training performance, right-hander Juan Nicasio will make his Pirates debut in their series finale against the Cardinals at 7:05 p.m. ET at PNC Park. Nicasio struck out 24 batters in 15 scoreless innings this spring, beating out Ryan Vogelsong for the final spot in Pittsburgh's rotation.
Watch every out-of-market regular season game live on MLB.TV.