The Pittsburgh Pirates survived a nearly five-hour marathon to keep their winning streak going and extend the Colorado Rockies' slump.

Neither team has much time to rest up.

Pittsburgh looks to hand Colorado a sixth consecutive defeat by completing a four-game sweep in Thursday's matinee at Coors Field.

The Pirates (13-9) got three homers from Andrew McCutchen in Tuesday's victory before jumping out to a 7-0 lead the following night. The Rockies (9-12) rallied to tie it the eighth, but Jordy Mercer's two-out RBI double in the 12th gave Pittsburgh a 9-8 victory.

Gregory Polanco homered and David Freese and Francisco Cervelli joined Polanco and Mercer with a pair of RBIs for the Pirates, who have scored 36 runs while winning four in a row.

''We keep playing,'' manager Clint Hurdle said. ''We play with emotion, not emotionally.''

They've also won seven straight in the series, all in Denver to extend their winning streak there to eight.

Colorado lost for the second time during its skid when scoring at least eight runs. It also marked just its second defeat in the last four seasons when hitting at least four homers as Gerardo Parra, Trevor Story, Nolan Arenado and Mark Reynolds all went deep.

Story's homer gives him an NL rookie record with nine in April, breaking the mark Albert Pujols set with St. Louis in 2001. He hadn't homered in his previous six games, during which he went 2 for 22 and struck out eight times.

Each of the Rockies' defeats during their skid has come at Coors Field, where they've been outscored 96-69 while allowing fewer than four runs once in 12 games.

''We've lost some tough ones. But sometimes that's the price you pay for fighting your way back into games, and you end up getting your heart broken because you keep competing,'' manager Walt Weiss said.

These clubs will get back at it quickly with a 12:10 p.m. local time start. Colorado will hand the ball to Tyler Chatwood, who is coming off his worst outing of the season.

After going at least six innings in each of his first three starts, Chatwood (2-2, 3.47 ERA) labored through four while giving up three runs and throwing 95 pitches in a 4-1 loss to the Los Angeles Dodgers on Saturday.

Such elevated pitch counts could make for shorter outings down the road after he missed all of last season recovering from Tommy John surgery.

''I didn't have command of anything really,'' Chatwood said. ''It was just not very good overall.''

The right-hander has never faced the Pirates, who will counter with Juan Nicasio as he faces his former team.

Nicasio (2-2, 4.50) started exclusively in his first three seasons with Colorado before coming out of the bullpen half the time in 2014, finishing with a 5.03 ERA in four seasons. He was dealt to the Los Angeles Dodgers prior to last season and allowed two runs in 6 2/3 innings over one start and five relief appearances against his former team.

The right-hander signed with the Pirates in December and has been so-so. He gave up two runs and walked four in five innings of a 7-1 loss at Arizona on Saturday.

Nicasio has a 5.32 ERA in 37 starts at Coors Field.