It was what happened next that made the difference, as the Pirates fell, 3-2, to the Nationals to open a four-game series.
Duke kept the Nationals hitters away from the bases for most of the game, using all of his available pitches and locating them better with each batter that he faced.
"For me, it was getting back to throwing the ball where I want to throw it," he said. "Just being able to mix up all the pitches for strikes."
Duke left in the seventh with the game tied at 2. In the eighth, reliever John Grabow gave up a single to Cristian Guzman that bounced just inside the first-base foul line to open the inning.
After getting an out, he worked cleanup hitter Nick Johnson into a 3-2 count before overthrowing a fastball that hit Johnson, costing him an out.
Two batters later, Austin Kearns waited on Grabow's changeup and sent it to right field, getting it to drop and scoring Guzman.
"It's a pitch I've been getting guys out with recently," he said. "If I get that ball down, maybe it's a ground ball."
Both teams were looking for a win for the same reasons -- last-place teams who were putting struggling pitchers on the mound. Both pitchers left with confidence, but it was the Nationals who stole the victory.
Perez allowed just three hits, but two of them were home runs. Freddy Sanchez had a solo shot in the fourth and then Ryan Doumit added another in the seventh. Doumit said that hitting Perez was difficult because of the number of strikes he threw.
"He was ahead to almost every hitter," Doumit said. "It's tough to hit a baseball, anyway. When a guy can spot like that, it's even harder."
Doumit was more appreciative of Duke's strong outing, which he saw from behind the plate. After a rough second inning, where he allowed three singles and two runs, Duke gave up just one more hit before leaving at the end of the seventh. His 85-pitch outing was ended by a pinch-hit situation.
"As the game went on, he threw better and kept us in it," manger John Russell said. "I thought he did a great job."
Washington's first runs went to Lastings Milledge and Kearns, who were driven in by catcher Wil Nieves.
But after that, the game settled into a defensive groove.
Russell said that he felt that Duke had just been making mistakes at bad times this season, but on the whole, had been throwing the ball well.
On Thursday, he had no such blunders, but neither did Perez, another pitcher who was looking for something to bounce his way. Duke remains with an 0-2 record; Perez, 0-3.
The stalemate gave way in the eighth with Grabow on the mound, then the Pirates were unable to get a hit against Jon Rauch in the ninth.
"I was a little erratic," Grabow said. "That's not like me."
On Friday, the Pirates have their work cut out for them offensively against John Lannan, who, to date, has been the Nationals' best pitcher. They'll want to get some runs and build confidence early for Phil Dumatrait, who is making his first start of the season.
Russell said that he saw promising signs from his hitters on Thursday and thinks things will work out for the Bucs.
"We swung the bat well, but they played great defense," he said.
Michael Phillips is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.