PITTSBURGH — Virgil Vasquez took full responsibility for the Pirates' defeat on Wednesday night.

“I didn't give us a chance to win,” the Pirates rookie right-hander said.

While that was a nice gesture, Vasquez was not totally to blame for the Pirates’ 4-1 loss to the Chicago Cubs at PNC Park.

The Pirates scored one run or less for the 20th time this season as they were stymied by rookie Randy Wells and the Cubs' bullpen.

Wells (3-3) held the Pirates to one run and six hits in seven innings.

Carlos Marmol pitched a scoreless eighth and Kevin Gregg worked a perfect ninth for his 14th save in 17 opportunities.

That sent the Pirates to their third defeat in their past four games as they lost twice in the three-game series.

“Wells threw a great game against us,” Pirates manager John Russell said. “He threw all his pitches for strikes and really made good pitches when we had some opportunities to do something. He was very effective. Then, when you put them in a situation where they can bring the backend of the bullpen into the game, it’s tough to come back.”

While shortstop Jack Wilson also praised Wells, he saw the Pirates' inability to score more than one run as another sign of the malaise that has struck the offense for much of the season, even before center fielder Nate McLouth and left fielder Nyjer Morgan were traded. The Pirates have scored three runs or less in exactly half,

39 of 78, of their games.

“We fall into these ruts where we can’t produce any runs, where we can’t a big hit when we need one,” Wilson said. “We’ve got to find a way to be more consistent. We need to score runs. We’ve gotten a lot of good pitching performances this season and haven’t capitalized on them.”

Though Vasquez (1-1) was hurt by a pair of home runs in his second start since being recalled from Class AAA Indianapolis, he pitched reasonably well in allowing three runs and seven hits in six innings with three walks and two strikeouts.

Derrek Lee hit a two-run homer to center in the first inning to open the scoring and Kosuke Fukudome’s solo shot to right-center in the sixth made it 3-1.

However, Vasquez was far from satisfied after he had given up two runs in six innings to beat Kansas City for his first major-league victory last Friday.

“This start wasn’t nearly as good as the last one,” Vasquez said. “I never got into any kind of rhythm. I didn't make nearly enough good pitches.”

Vasquez was particularly bothered by the three walks. He allowed only 10 bases on balls in 792/3 innings with Indianapolis this season.

“I got behind in the count too often and had too many long innings,” Vasquez said.

“I’m a pitch-to-contact guy and it was like I was shying away from letting them hit the ball. My job is to get our guys off the field and in the dugout as quickly as I can so they can swing the bats. I didn’t have quick innings and our hitters were never able to get into a rhythm because they were standing around in the field too long”

The Pirates got their run off Wells in the first on Brandon Moss’ RBI single to cut the deficit to 2-1.

The only other time the Pirates put a runner in scoring position was the fifth. However, Wilson was thrown out at home by left fielder Sam Fuld to end the inning as he tried to score from second base on Freddy Sanchez’s single.

The Cubs added a run in the eighth as Geovany Soto hit an RBI single off Steven Jackson to increase their lead to 4-1.

Cubs manager Lou Piniella was ejected in the middle of the sixth inning by first base umpire Chad Fairchild. Piniella slammed his cap to the ground while arguing that Wells beat out a comebacker to Vasquez for what turned out to be the third out of the inning.