The Colorado Rockies got a big swing from their best player and mostly played well in a place that has not been kind to them throughout their history but another seventh-inning collapse ultimately led to a St. Louis Cardinals walk-off 5-4 win in extras.

Both starters, Carlos Martinez and Tyler Anderson, pitched well in the early going but left the field handing a tough spot to their respective bullpens, ultimately ending in neither earning a decision.

Nolan Arenado came into this series in St. Louis with over 50 at-bats in Busch Stadium without having recorded a home run or even an RBI.

That all changed in the fifth inning. A pair of singles from Gerardo Parra and Charlie Blackmon plus a walk from Ian Desmond brought the Colorado Rockies superstar to the plate with the bases loaded and two outs. Rookie pitcher Daniel Poncedeleon (what a name!) left a fastball over the middle of the plate after inheriting the tough situation and Arenado launched it over the wall in deep center to break a scoreless tie in emphatic fashion.

It was the first grand slam ever hit by a Rockies player in St. Louis. It was Arenado’s 28th home run of the season and brought his RBI total to 79.

The Cardinals got a run back in the bottom of the fifth on Anderson’s first mistake of the game. Jedd Gyorko jumped on a center-cut fastball and blasted it into the left-field seats to get the Cards on the board.

It looked like the Rockies got another run in the sixth with a two-out rally. Gerardo Parra singled to center and advanced to third on a botched pickoff attempt. Poncedeleon then unleashed a wild pitch to the backstop and Parra raced home, appearing to avoid the tag at the plate. Replays looked inconclusive to this reporter but surprisingly the call was changed upon review, taking what would turn out to be a very important run off the board for the Rockies.

But the wheels came off the wagon for the Rockies starter in the seventh. He appeared to lose the feel for most of his pitches throughout the inning, walking the bases loaded before needing to be replaced by Scott Oberg.

Oberg looked for a moment like he might escape the jam unscathed when he struck out Dexter Fowler. But he lost Harrison Bader, walking in a run. Then he got the groundball he was looking for but it wasn’t hit hard enough, Arenado electing to come home to prevent another run from scoring, but there was no chance for the double play.

The hot-hitting Matt Carpenter was given an opportunity with two outs and delivered a huge single back up the middle on a slider that Oberg hung just a little bit. And with that, the Cardinals tied the game at four runs apiece.

Seunwhan Oh replaced Oberg and got Yadier Molina to fly out to left. He stayed on for the eighth and allowed a two-out single to Gyorki but otherwise worked a clean inning.

Garrett Hampson singled with one out in the ninth and stole second. He moved up to third but was stranded there for the second time in the game when Charlie Blackmon ground out to second.

Adam Ottavino came on in the bottom of the ninth and gave up a leadoff single to Fowler, who has a sub .200 batting average on the season. Fowler then stole second but Otto struck out Bader, got Greg Garcia to ground out and Molina to line out to right to send the game to extra innings.

The Rockies got a pair of baserunners in the 10th thanks to a leadoff walk from Desmond and a two-out single by Ryan McMahon but Tom Murphy struck out to strand them.

Jake McGee took over in the bottom of the 10th and struck Paul DeJong but grooved a fastball to Marcell Ozuna that he ripped over the wall in left-center field for the walk-off home run.

Final Stats:

Tyler Anderson: 6 IP, 3 H, 4 ER, 3 BB, 5 K

Scott Oberg: 0.2 IP, 1 H, 0 ER, 1 BB, 1 K

Seungwhan Oh: 1.1 IP, 1 H, 0 ER, 0 BB, 1 K

Adam Ottavino: 1 IP, 1 H, 1 BB, 1 K

Jake McGee: 0.1 IP, 1 H, 1 ER

Nolan Arenado: 2-for-5, 1 R, 4 RBI (HR: 28)

Gerardo Parra: 2-for-4, 1 R

Ian Desmond: 0-for-2, 1 R, 3 BB

Charlie Blackmon: 1-for-5, 1 R