After two games in which the Pirates' starters combined to pitch seven innings, Duke managed one more than that on his own. The left-hander got in a groove early and matched Cubs starter Jason Marquis inning-by-inning through six frames.
"He pitched with what he does best," manager John Russell said. "He was doing what he does instead of letting the hitter dictate. Some pitchers get caught up with the idea that you've got to pitcher certain hitters certain ways. That takes you out of what your strength is."
That was an encouraging sign from Duke, who entered the game on a personal eight-game losing streak. Without a win since the second week of June, Duke continued to employ a slight change in his mechanics and afterward credited the adjustment with aiding in his success.
Before his last start, Duke and pitching coach Jeff Andrews readjusted Duke's motion so that he started his windup with his hand higher. In turn, Duke stands taller on the mound, improving his downward motion toward the plate.
"Obviously, I'm just going to keep building on what I've been building on," he said. "I feel like the work I'm doing is in the right direction. I just have to keep executing pitches."
But while successful with the new delivery, it would be a bad-luck seventh that pushed Duke to 4-13 on the season.
After giving up five hits in the first six innings, Duke allowed a leadoff single to Reed Johnson, who took advantage of Andy LaRoche playing deep at third. Johnson bunted the ball down the third-base line and easily made it to first.
"He wasn't moving, so I decided that was a good opportunity to get on base, especially with leading off the inning there," Johnson said.
A double to Mark DeRosa followed. And soon after, so would two RBI hits that traveled less than 90 feet combined.
Ronny Cedeno knocked a short dribbler down the third-base line that LaRoche charged in and barehanded. With little chance to get the runner at the plate, LaRoche threw to first for the out.
Chicago catcher Henry Blanco then put down a suicide squeeze bunt just a few feet from home plate. But it stayed just inside the foul line, and the Pirates infielders who all converged on the play had no shot to get DeRosa at the plate.
"Tip your hat to them for knowing how to manufacture stuff like that," Duke said. "One ball left the infield and they got two runs. What can you do about that?"
Duke would go on to finish the eighth as well, giving him his first eight-inning start of the season. But the damage was done. He finished with six strikeouts and walked just two.
"I feel like I did pretty well today, especially against that offense," he said. "Marquis was on his game and there's nothing that we can do. There's been a couple games like this where I've thrown very well and just not gotten the results just, because I've gone up against a guy that's just a little bit better. It will turn around."
Marquis, who came into the game with a 3.81 ERA in four August starts, was quite the formidable opponent on the other end. One day after the Pirates scored nine runs, the team was shut out for the fifth time this season.
There was little noise on the offensive end altogether, as Pittsburgh finished with just five hits. Catcher Raul Chavez contributed two of them. Twice, the Pirates managed to move a runner to third with two outs, but the club could not cash in on either opportunity.
Not to be lost in the result, newcomer Jesse Chavez also made his Major League debut in this game, pitching a 1-2-3 ninth.
"I'm excited to be here," Chavez said. "I'll just be ready when that phone rings."
After an off-day on Thursday, the Pirates will try to break their seven-game skid, their longest such streak this season, against the Brewers on Friday.