PITTSBURGH (AP) - The Colorado Rockies spent two innings pushing around Pittsburgh starter Francisco Liriano. They just couldn't push him over.
The Pirates didn't waste the reprieve or a rough night by the Colorado bullpen.
Travis Snider's pinch-hit double in the eighth scored Neil Walker with the go-ahead run as Pittsburgh scrambled to a 4-2 victory on Friday night.
It was a start to the second half that looked an awful lot like most of the first half for a team that began the night tied for the fewest wins in the National League.
''You've got a guy on the ropes and you don't capitalize, it's usually going to come back to bite you,'' Colorado manager Walt Weiss said.
Charlie Culberson and Corey Dickerson had two hits apiece for the Rockies, but Colorado's bullpen couldn't give starter Jorge De La Rosa his fifth consecutive victory.
The Rockies left 11 runners on base while losing their third straight, including four in the first two innings when they managed just one run despite loading the bases in both frames.
''Liriano has been good for a while because he can pitch out of jams and did a nice job working his way out of those two jams the first couple innings,'' Weiss said.
The Rockies still held a 2-1 lead in the seventh after six steady innings from De La Rosa before things fell apart. The Pirates loaded the bases against Rex Brothers, and reliever Adam Ottavino's 0-2 fastball ended up smacking Starling Marte's helmet to tie the game.
''It was a bad pitch, I wish it didn't happen,'' Ottavino said. ''It got away from me.''
Pittsburgh went ahead in the eighth. Walker led off with a single and moved to third on Gaby Sanchez's liner up the middle.
Snider followed with his major league-leading 11th pinch hit of the season, a hard drive that right fielder Carlos Gonzalez couldn't track down, the low point on a night the slugger also struck out five times.
Tony Watson (6-1) picked up the win with a scoreless eighth inning. Mark Melancon got Troy Tulowitzki, representing the tying run, to ground out to third to end it for his 17th save.
Liriano worked five innings as he tries to bounce back from a difficult first half in which he managed just one win in 15 starts and spent a month on the disabled list with a back injury. The left-hander returned in four shaky innings last weekend against Cincinnati, but manager Clint Hurdle threw Liriano right back out there on Friday hoping to get him into a comfortable rhythm.
The early signs were encouraging. Liriano labored through the first two innings - needing 27 pitches to get out of bases-loaded jam in the first - but got better as the game wore on. Colorado managed only an RBI fielder's choice by Dickerson in the second against him as he retired 11 of the last 12 batters he faced.
Liriano allowed one run on three hits, walking three and striking out eight.
De La Rosa was just as effective while keeping the Pirates off balance for six innings. Poor decision making by Marte helped. The left fielder tripled to left with two outs in the fifth, scoring Polanco all the way from first. Marte then ran through third baseman Nick Leyva's stop sign and was out by a good 15 feet trying for an inside the park homer.
Still, the Pirates picked up their 23rd comeback win of the season by hanging in there despite three errors.
NOTES: Pittsburgh RHP Gerrit Cole threw 30 pitches on Thursday without incident as he recovers from a sore back. Cole was eligible to come off the disabled list on Friday but the team remains uncertain on when he will return. ... Colorado RHP Tyler Chatwood will have undergo reconstructive elbow surgery for the second time in his career. Chatwood hasn't pitched since going on the 60-day disabled list on April 30. The 24-year-old is 20-22 with a 4.34 ERA in 70 major league games. He is expected to miss 12-18 months. ... The series continues on Saturday when Pittsburgh's Charlie Morton (5-9, 3.32 ERA) faces Colorado's Brett Anderson (0-3, 4.95).