PITTSBURGH -- Zach Duke didn't have his best stuff Thursday night. He did have the concentration that has marked his impressive rookie season.
"It was a struggle, to be honest with you. My control wasn't there, but I was able to come up with big pitches when I needed them," Duke said. "You have to focus on each pitch, each situation."
Duke (3-0) had pitched 22 consecutive innings without allowing a run before the Rockies scored an unearned one in the sixth inning. He got Danny Ardoin to ground out with a man on third in the second and retired Matt Holliday on a fly ball with the bases loaded in the third.
"He's shown the ability to add a little, reach back a little more when he needs to," Pirates manager Lloyd McClendon said. "When he did get into trouble, he made some quality pitches."
Jason Bay went 3-for-4 with a homer and Humberto Cota drove in three runs with two singles for the Pirates, who had scored only 16 runs in their previous nine games.
Bay followed Matt Lawton's one-out single in the second with a homer to left, his 18th, to stake the Pirates to a 7-0 lead. Bay singled and scored in a five-run first off starter Jeff Francis.
Francis (8-7) allowed eight hits and seven runs in 1 1/3 innings and lasted just five innings. After winning three consecutive starts, Francis is 0-2 in his last three starts and has allowed 18 earned runs in that span.
The loss followed a 3-2 win at Washington on Wednesday that gave the Rockies their first series victory on the road this season.
"Your momentum is as good as your starting pitching," Colorado manager Clint Hurdle said. "Theirs was good and ours wasn't good. After the first two innings Francis settled down and got us to the sixth, but way too much damage was done early."
By the time Cota singled off reliever Marcos Carvajal to score Jose Castillo with two outs in the seventh, the Rockies were well on their way to their 38th road loss of the season.
The Pirates sent 10 men to the plate in the first inning and used six singles to score five runs -- all with two outs. It marked the first time since July 9 the Pirates scored more than one run in an inning.
"We haven't swung the bats very well. We haven't done much very well lately," Bay said. "So it was nice to get out to a lead early and not put any pressure on ourselves. It's nice to go out there and play and have a little fun."
Francis allowed a single to leadoff hitter Chris Duffy and was one out away from getting out of the first inning when Bay singled. Castillo followed with a single to center, scoring Duffy.
Daryle Ward snapped an 0-for-30 slump with a single to right, scoring Bay, and took second when Ardoin misplayed Eric Byrnes' throw home. Cota singled to drive in two and Jack Wilson's single added one more.
"I just got ahead of myself as far as trying to do a lot of things at once instead of keeping things simple," Francis said. "I've been telling myself that for a year."
The Rockies' run came with no outs in the sixth. Holliday and Mohr singled to start the inning, and Desi Relaford followed with a ground ball up the middle that was fielded by shortstop Wilson. Wilson forced Mohr at second, but his throw to first bounced and struck Ward in the face, allowing Holliday to score from third.
"Duke was as advertised," Hurdle said. "He was very efficient for a young pitcher."
Ward's RBI in the first inning was his first since July 3 ... The Rockies have been outscored 36-4 in the first inning on the road this season ... Bay's homer was just his fifth at PNC Park this season. ... Duke's scoreless streak was the longest by a Pittsburgh pitcher since Kip Wells went 22 1/3 innings in 2002 ... Colorado has lost seven consecutive series to the Pirates since May 2002. ... Relaford snapped an 0-for-33 slump with an eighth-inning single.