Neil Walker had a career-high six RBIs, including a three-run homer, and the Pittsburgh Pirates clinched their third straight playoff berth by beating the Colorado Rockies 13-7 on Wednesday night.

The Pirates secured at least a wild card as they chase first-place St. Louis in the NL Central. They trail by four games with a home series coming up against the Cardinals.

St. Louis and Pittsburgh are the only major league teams to lock up playoff trips so far.

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Walker provided the bulk of the offense with a bloop, two-run single in the first and a towering three-run homer in the third off fill-in starter Christian Bergman (3-1). Walker ended his night with a run-scoring single as part of a six-run ninth to break open a tight game.

Charlie Morton allowed the Rockies to climb within a run after being staked to a 7-1 lead. Joe Blanton (4-0) tossed 1 2-3 scoreless innings.

Starling Marte had three hits, including a two-run double. He didn't have the game-winning hit, though, noteworthy because he's delivered it the previous two seasons when the Pirates locked up a playoff spot.

Just when the Pirates appeared on their way to a rout, things got interesting in the fifth after Morton allowed a solo homer to Corey Dickerson and a three-run shot to Tom Murphy, making it 7-6.

Blanton and the bullpen kept the Rockies at bay. Sean Rodriguez hit a three-run double to spark the big ninth.

Bergman never found a groove during his second start of the season. He allowed seven runs and 10 hits in 3 2-3 innings.

Pittsburgh manager Clint Hurdle said before the game he wasn't sure how rowdy the celebration would be should his team clinch, but the players have certainly earned the right to let loose a little bit. The Pirates (92-60) are making their third consecutive trip to the postseason, a streak they also accomplished from 1970-72 and 1990-92.

"We know how hard we've worked," Hurdle said. "We know what we've poured into this. We know what we've committed to this."

TRAINER'S ROOM

Pirates: 3B Aramis Ramirez sat out after tweaking his groin the night before while legging out a triple. He said he felt it grab on his way from second to third.

Rockies: OF Charlie Blackmon was a late scratch with a stiff neck. ... OF Brandon Barnes left the game with a mild left hamstring strain. ... 3B Nolan Arenado was given the night off after hitting his head while diving for a ball Tuesday. ... Manager Walt Weiss said LHP Jorge De La Rosa won't pitch again this season due to right Achilles tendinitis.

UP NEXT

Pirates: LHP Jeff Locke (8-11, 4.48 ERA) will tie a career high with his 30th start of the season Thursday.

Rockies: RHP Chad Bettis (8-5, 4.46) is 2-0 with a 0.75 ERA in his last two starts -- wins over Seattle and San Diego.