CHICAGO -- Four bad pitches.

That was all Pittsburgh manager John Russell needed to see from starter Ross Ohlendorf to make a move that he had to know would be questioned, given the outcome.

Russell's decision to pull Ohlendorf four pitches into the seventh set on course a sequence of events that ultimately cost the Pirates the opportunity to secure a second consecutive series sweep over the Cubs. Instead, three late Chicago runs sent Pittsburgh to a 4-3 loss at Wrigley Field on Sunday and left Russell having to explain why he turned to the bullpen as early as he did.

The Pirates had all the momentum heading into the seventh. They had taken an early three-run lead against a Cubs team that had lost nine of its previous 11. And with Ohlendorf notably efficient, the Pirates' 14-0 record when leading after six innings hardly seemed in jeopardy.

Ohlendorf, having thrown only 69 pitches, took a 3-1 lead into the inning. He had just hit for himself in the top half of the frame with the Pirates one big hit away from putting the game out of reach, which certainly suggested that Russell had no immediate plans to remove the right-hander.

But Ohlendorf opened the seventh with four pitches -- including three fastballs -- all missing badly. As Mike Fontenot took first, Russell came out to take the ball from Ohlendorf.

"With the first hitter there, you could tell he really lost his rhythm," Russell said, explaining the quick hook. "He missed pretty badly on four pitches."

Ohlendorf, who showed visible frustration during the four-pitch sequence to Fontenot, was asked if felt like he could have continued given his low pitch count and success to that point.

"When you walk a guy on four pitches to start an inning, you're not really showing a manager that you're still good to go, even though I felt good and wanted to stay in," Ohlendorf said. "I could see why he wanted to make the move. I just wish I had given him a reason not to. I felt fine."

To that point, Ohlendorf's only stumble had been in the second, when he allowed one run to score, but otherwise worked out of a messy jam.

"I was set up for it to be a really good start, but then walking the guy made it kind of disappointing," he said.

So, too, did the ending.

From Ohlendorf, Russell handed the ball to Evan Meek, the team's most reliable reliever all season. Diving catches by outfielders Andrew McCutchen and Ryan Church had Meek poised to leave that runner stranded, but the righty couldn't close the door.

A single by Kosuke Fukudome skirted just past second baseman Bobby Crosby. Meek then misfired on a two-strike curveball that went to the backstop. The wild pitch brought Chicago to within one.

"We were trying to go away and the ball cut," Meek said. "It wasn't a good pitch."

The next mistake came from shortstop Ronny Cedeno, who couldn't cleanly field a potential inning-ending chopper up the middle.

"Hit me here," Cedeno said, pointing to his chest. "Bad hop."

Two pitches later, Derrek Lee came through with the game-tying RBI single.

"They didn't hit anything hard," said Meek, who was charged with his second blown save of the year. "They just happened to find holes. Unfortunately, that stuff is going to happen."

From there, the momentum seemed all Chicago's. The Cubs took their first lead the following inning against Pirates reliever D.J. Carrasco. Heads-up baserunning by Alfonso Soriano -- who moved from first to third with two out when Carrasco threw a pitch to the backstop as Soriano was trying to steal second -- put him into position to score on Xavier Nady's two-strike, pinch-hit RBI single.

"I just didn't have my offspeed there today," said Carrasco, who appeared in every game this series. "I don't think I threw one slider for a strike. It was just all bad today -- all the breaking balls."

The Pirates went down quietly in the ninth to have their seven-game winning streak against the Cubs snapped.

While the Pirates' bullpen cost Ohlendorf what would have been his first win of the season, the club's offense never helped extend the lead either. After RBI hits by Crosby and Lastings Milledge gave the Pirates a 3-0 lead in the second, Cubs starter Ted Lilly shut Pittsburgh down for the rest of his seven-inning stint.

The Pirates' best chance to tack on some runs came in Lilly's final inning of work, which began with consecutive singles. A flyout failed to advance either runner. Ohlendorf then came up to hit for himself. The plan was to have him lay down a sacrifice, but when he saw Chicago's infield put on the wheel play, he pulled back to swing.

Ohlendorf lifted a ball over a drawn-in outfield, but Fukudome made a sensational running catch to save at least one run from scoring.

"I think that was kind of the turning point of the game right there," Russell said. "If that ball drops, it might have been a whole different story."

Pittsburgh managed to load the bases, but Andy LaRoche's infield popup ended the threat.

The loss kept the Pirates from tallying eight straight wins over the Cubs for the first time in 20 years. It also marked just the second time this season that the bullpen was charged with the loss.

"Being in a game like this, being ahead, it would have been nice to take the game," Meek said. "Taking the series is nice, but you want to take a game that you're supposed to win."